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LIQUID FUEL 

AND ITS APPARATUS 



LIQUID FUEL 

AND ITS APPARATUS 



By Wm. H. BOOTH, F.G.S. 

MEMBER OF THE AMERICAN SOCIETY. OF CIVIL ENGINEERS J FORMERLY 

OF THE NEW, SOUTH WALES GOVERNMENT RAILWAYS AND 

TRAMWAYS, OF THE MANCHESTER STEAM USERS' 

ASSOCIATION, OF THE BRITISH ELECTRIC 

TRACTION COMPANY, ETC. 



SECOND EDITION 



NEW YORK 
E. P. DUTTON AND COMPANY 

PUBLISHERS 



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Printed in Great Britain by 
Butler & Tanner, 
Frame and London 



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4d 

table of contents 

Mi) 

PART I 
THEORY AND PRINCIPLES. 

PAGE 

Preface • • . . . . . . • .13 

INTRODUCTION 

Historical Notes ; Advantages of Liquid Fuel ; Petroleum ; 

General Notes ; Economies possible by the use of Liquid Fuel 21 

CHAPTER I 

The Geology of Petroleum ; Petroleum Drilling ; Pumping . 28 

CHAPTER II 

The Economy of Liquid Fuel ; The Dangers of Petroleum ; Air 
necessary for Combustion ; General Principles of Liquid 
Fuel Combustion ; Flame Analysis ; Refractory Furnace 
Linings ; The Weir Boiler ; Liquid Fuels ; The necessity for 
Atomizing ; Vapourizing ; Varieties of Liquid Fuel ; Ameri- 
can Petroleum ; Russian Petroleum ; Creosote Oils ; Tar 
Distillates ; Blast Furnace and Shale Oils ... 35 

CHAPTER III 

Texas Oil ; Analysis of Oil ; Physical Properties ; Russian Oil ; 
Calorific Capacity of Oils ; Advantages of Liquid Fuel ; The 
Use of Oil on Locomotives ; The World's Oil Production ; 
The Limits of Liquid Fuel ; Equivalence of Oil and Coal ; 
Tests of Texas Oil 48 

CHAPTER IV 

Chemical and other Properties of Petroleum ; Water in Oil ; 
Petroleums suitable for Fuel; Physical Properties of Petro- 
leum ; Specific Gravity of Petroleum ; Materials ; Cast 
Iron ; Steel ; Firebricks ; Fireclay ; Clay Analysis ; Special 
Forms of Bricks ; Classification of Clay Goods . 62 



6 TABLE OF CONTENTS 

CHAPTER V 

PAGE 

Combustibles and Supporters of Combustion. Carbon : its 
Forms and Origin ; its Calorific Properties ; its Combustion 
and Chemistry. Hydrogen : its Physical and other Pro- 
perties ; its Compounds with Carbon ; its Combustion ; 
Air ; The Atmosphere ; Properties of Air. Oxygen : its 
Compounds with Carbon ; its Properties ; Water ; its 
Properties ; Origin and Sources of Water Impurities ; Solu- 
bility of Salts ; Sea Water ; Useful Data ... 78 

CHAPTER VI 

Calorific and other Units ; Thermo Chemistry ; Heat ; Tem- 
perature ; Thermometers ; Specific Heat ; Latent Heat ; 
Dissociation ; Units of Heat ; Units of Work ; Units of 
Weight ; Gravity ; Compound Units ; Calorific Power of 
Fuels ; Calculation of Temperatures ; Effects of Dissocia- 
tion and of Variation of Specific Heat ; Relative Volumes 
produced by Combustion ; Evaporative Power of Fuel ; 
Temperatures due to Combustion ; Calculation of Calorific 
Capacity of Fuels ; Smoke and Combustion ; Varieties of 
Smoke ; Its Prevention ; Influence of Refractory Furnaces ; 
The Combustion of Bituminous Fuels ; Carbon Vapour ; 
Liquid Fuels ; Furnace Temperatures ; Theoretical Flame 
Temperature ; Total Heat generated ; Air Supply ; The 
Heat Properties of Carbon ; The Process of Coal Combus- 
tion ; Effect of Vaporizing Solid Fuels ; Flame Analysis ; 
The Principles of Combustion ; The Necessity of Tem- 
perature ; Smoke due to Loss of Heat of Burning Gases ; 
The Use of Coloured Glass for Flame Inspection ; The Weir 
Boiler ; Ringelmann's Smoke Chart .... 90 



PART II 
PRACTICE. 

CHAPTER VII 

Oil Storage on Ships ; Example of Improvised Tank Steamer ; 
Example of Cargo Steamer ; Example of New Tank 
Steamer ; Use of Liquid Fuel at Sea ; Supply of Oil at 
Ports ; Safety and Flash Point ; Advantages for War Ships ; 
Economic Advantages of Liquid Fuel . . . . 127 

CHAPTER VIII 

Marine Furnace Gear ; Arrangement of Shell Line Steamers ; 
Interchange of Coal and Oil ; The Flannery-Boyd System ; 
The Orde System ; Results of Use of Liquid Fuel at Sea ; 
Wallsend Slipway Company's Arrangement ; The Lanca- 
shire Boiler with Orde's System ; Korting System ; Howden 
System .......... 133 



TABLE OF CONTENTS 

CHAPTER IX 



PAGE 



Liquid Fuel Application to Locomotives ; The Holden System ; 
Advantage of Oil ; Method of Working ; Management of 
Fire ; Particulars of Oil Burning Locomotive ; Regulation 
of Oil Supply ; The Atomizer ; Life of Fire Boxes ; Heating 
the Oil ; Air Heater ....... 154 



CHAPTER X 

Application of Liquid Fuel to Stationary and other Boilers ; The 
Lancashire Boiler ; Cornish Boiler ; Water Tube Boiler ; 
Locomotive Boiler ; Level of Atomizer in Mixed System ; 
Management of Fire ; United States Navy Tests ; The 
Meyer System ; The Mixed System of Coal and Liquid Fuel 
Combustion : its use in the Italian Navy ; M. Bertin's 
Calculations . ■ . . . . . . . . 167 



CHAPTER XI . 

Russian and American Locomotive Practice ; The Baldwin Com- 
pany's System ; The Equivalence of Coal and Oil ; Compari- 
sons of Cost of Liquid Fuel ; The Danger of Crude Oil ; The 
Urquhart System ; General Arrangements ; Management of 
Furnace ; Firebox Designs ; Smoke Results on Grazi and 
Tsaritsin Railway . . . . . . . .178 



CHAPTER XII 

American Stationary Practice with Liquid Fuel ; The Billow 
System ; Fuel Oil Pumping Systems ; Double Pumping 
Systems ; Furnace Construction ; Operating a Fuel Oil Plant ; 
Examples of Boilers with Liquid Fuel Furnaces . . 195 



CHAPTER XIII 

English Stationary Practice with Liquid Fuel ; The Kermode 
System ; Analysis of Borneo Oil ; Tests of Borneo Oil ; 
The Hydr oleum System ; Tests ; The Sprayer ; Air Supply . 208 



CHAPTER XIV 

The Combustion of Vaporized Liquids ; The Clarkson-Capel 

Burner: its Various Applications; Starting Devices . .218 



CHAPTER XV 

Comparison of Air and Steam Atomization ; The Ellis and Eaves 

System ; Steam Atomization ; Air Atomization ; Tests . 222 



8 TABLE OF CONTENTS 

CHAPTER XVI 

PAGE 

The Storage and Distribution of Liquid Fuel ; Tanks ; Piping ; 
Ventilation ; Great Eastern Railway System ; Grazi and 
Tsaritsin Railway System ; Oil Pumps ; Flue Gas Analysis ; 
Calculation of Volumes ; The Orsat Apparatus ; C0 2 
Recorders ; Calorimetry and Draught ; Calorimetric Deter- 
minations ; Draught ; Gauges ; Difference of Solid and 
Liquid Fuel in Relation to Draught . . . . 228 

CHAPTER XVII 

Compressed Air ; Air Compressors ; Principles of Compression ; 
Weight of Air necessary for Liquid Fuel Atomization ; Adia- 
batic Calculation of Air ; Compound Air Compression ; 
Volumetric Efficiency ; Power to Compress Air ; Outflow of 
Air 242 

CHAPTER XVIII 

Atomizing Liquid Fuels ; Various Atomizers ; Elementary Forms ; 
Vaporizers ; The Symon-House Burner ; Atomizing Agents ; 
French Trials ; Air Compression ; Certain Advantages of 
Steam ; d'Allest Atomizer ; Fvardofski System ; Russian 
Atomizers ; Object of Atomizing ; American Practice . . 250 

CHAPTER XIX 

Application of Liquid Fuel to Metallurgy ; The Hoveler System . 266 

CHAPTER XX 
The Oil Engine ; The Diesel and other systems .... 270 



PART III 
Tables and Data 281 



INDEX TO ILLUSTRATIONS 



FIG 
0. 
1. 

2. 
3. 

4. 

5. 

6. 

7. 

8. 

9. 
10. 
11. 
12. 



PAGE 

Hypothetical Section of Oil-bearing Strata ... 30 
Kiln Furnace ........ 74 

Form of Baffle 74 

Brick Fire Arch 75 

Shaped Bricks . . . . . . . .76 

Shaped Bricks ........ 76 

Unshaped Arch Bricks . . . . . . .76 

Weir Boiler 121 

Bingelmann Smoke Chart . . . . . .122 

Furnaces, s.s. Murex ....... 134 

Furnace Brickwork, s.s. Murex . . . . .135 

Furnace, s.s. Trocas . . . . . . .136 

Service Tank, Flannery-Boyd System . . . .137 

13 and 13a. s.s. New York 138 

14. Water Tube Boiler, Orde's System 141 

14a. Fuel Bunker, Draw-off Pipe 142 

15. Orde's Atomizer ........ 144 

16. Detail Arrangement for Lancashire Boiler, Orde's System . 145 
17 and 17a. Design for Oil Furnace, Wallsend System . 146 

18. Wallsend Pressure Burner .••••. 148 

19. Diagrammatic Arrangement, Wallsend System . .150 
19a. Detail Arrangement, Wallsend System . . . .150 

20. Water Tube Boiler, Wallsend System . . . .151 

21. Furnace, s.s. F. C. Laeisz ...... 152 

22. Atomizer, Korting System . . . . . .153 

22a. Atomizer, Korting System . . . . . .153 

23. Great Eastern Locomotive, Atomizer, Holden's System . 158 
Atomizer, Form (1911), Holden's System . . .159 
Atomizer, Locomotive Type, Holden's System . .160 
Great Eastern Locomotive, Holden's System, Firedoor . 161 
American Locomotive Firebox for Liquid Fuel . . 163 
Great Eastern Locomotive . . . . . .165 

Lancashire Boiler, Holden's System . . . .168 

Water Tube Boiler without Grate, Holden's System . 169 

MacAHan Variable Blast Pipe Cap . . . .170 

Locomotive Boiler, Southern Pacific R.R. . . .171 

Meyer System ........ 173 

Atomizer, Baldwin System . . . . . .179 

Oil Regulator, Baldwin System . . . . .179 

Locomotive Firebox, Baldwin System, Old . . .180 

Locomotive Firebox, Baldwin System, New . . .181 

9 



24. 
25. 
26. 
27. 
28. 
29. 
30. 
31. 
32. 
33. 
34. 
35. 
36. 
37. 



10 



INDEX TO ILLUSTRATIONS 



FIG. PAGE 

38. Goods Locomotive, Urquhart System . . .188 

39. Goods tender, Urquhart System . . . . .190 

40. Firebox, Urquhart System . . . . . .191 

41. Locomotive Firebox, Urquhart System . . . .192 

42. Atomizer, Urquhart System . . . . . .193 

43. Locomotive Performance Chart, Urquhart System . .194 

44. Atomizer, Billow System . . . . . 196 

45. Double Pumping System, Billow . . . . .198 

46. Tuyere, Billow System 199 

47. Tuyere Block, Air Regulator, etc., Billow System . . 200 

48. Tank Car Hose Connection . . . . . .201 

49. General Furnace Mouthpiece Arrangement, Billow System 202 

50. Underfired Boiler, Billow System . . . . 205 

51. Water Tube Boiler, Billow System . . . .206 
51a. General Arrangement, Billow System . . . . 207 

52. Liquid Fuel Furnace, Kermode's System . . . 209 
52a. Enlarged Details, Kermode's System . . . .210 

53. Furnace Arrangement, Kermode's System . . .211 

54. Furnace Arrangement, Kermode's System, Babcock Boiler 213 

55. Furnace Arrangement, Hydroleum System . . .215 

56. Furnace Arrangement, Hydroleum System . . .216 

57. Clarkson-Capel Burner for Fire Float .... 219 

58. Clarkson-Capel Burner for Automobile .... 220 

59. Air Heater, Ellis and Eaves System . . . .223 

60. Ellis and Eaves Furnace Door 223 

61. Oil Supply Tank 231 

62. Weir Pump 232 

63. Diagram of Adiabatic Compression. .... 244 

64. Diagram of Compound Compression with Intercooling . 244 

65. Atomizer, Hoveler System ...... 267 

66. Atomizer, Rusden-Eeles . . . . . . .251 

67. Atomizer, Aerated Fuel Process ..... 252 

68. Atomizer, Kermode's Pressure System . . . .253 

69. Atomizer, Kermode's Hot-Air System ... . . 254 

70. Atomizer, Kermode's Steam System .... 255 

71. Atomizer, Hydroleum System ..... 255 

72. Atomizer, Elementary Form ...... 256 

73. Atomizer, Swensson ....... 256 

74. Symon-House Vaporizer . . . . . .257 

75. Atomizer, Guyot ........ 258 

76. Atomizer, Nozzle Incorrect Form ..... 259 

77. Atomizer, Nozzle Correct Form . . . . .259 

78. Furnace of French Torpedo Boat No. 22 260 

79. Atomizer, d'Allest 261 

80. Atomizer, Double, d'Allest 262 

81. Atomizer, Soliani . . . . . . . .263 

82. Torpedo Boiler tried at Cherbourg .... 264 
82a. Assembly of Gregory's Fuel Oil Burner .... 265b 

83. Hornsby-Akroyd Engine . . . . . .272 

84. Cross Section, Vaporizer, Hornsby-Akroyd . . • 273 

85. Griffin Engine Vaporizer ...... 27G 



INDEX TO TABLES 



TABLE 

I Composition of Crude Oils 

II Calorific Capacity of Liquid Fuel Oils 

III Coefficient of Expansion of Crude Oil 

IV Calorific Capacity of Crude Oil 
V Table of the Properties of Gases (Kempe) 

VI Temperature Table 

VII Specific Heat of Gases . 

VIII Equivalents, Various 

IX Calorific Properties of Carbon 

X Tension of Aqueous Vapour . 

XI Relative Economy Oil and Coal 

XII Russian and Pennsylvanian Oils, Analysis of . 

XIII Comparative Trials of Petroleum Refuse 

XIV Conversion Table, Degrees Baume .... 
XV Heat of Combustion (B. Th. U.) and Air per Pound 

of Fuel 

XVI Theoretical Flame Temperatures . . . . 

XVII Weight and Volume of Gases .... 

XVIII Weight and Volume of Oxygen and Air for Combustion. 
Metric ........ 

XIX Weight and Volume of Oxygen and Air for Combustion. 
English ........ 

XX Theoretical Evaporative Value of Petroleum and Coal 

XXI Ignition Temperature of Gases .... 

XXII Conversion Tables for Evaporation and Combustion 

XXIII Temperature Determination by Fusion of Metals 

XXIV Volume and Weight of Dry Air 
XXV B. Th. U. in Water . * . 

XXVI Saturated Steam Data . 

XXVII Factors of Evaporation . 

XXVIII Heat Balance Table 

XXIX Heat Lost in Chimney Gases (Diagram) 



TAGE 

281 

281 
281 

284 
282 
284 
284 
285 
285 
286 
286 
286 
287 
288 

288 
289 
289 

290 

290 
291 
292 
292 
293 
293 
294 
294 
295 
296 
297 



PREFACE TO LARGER EDITION 

OF 1903 

THE subject of Liquid Fuel is one that has now been before 
the public about twenty-five years, but little had been 
done in this country until about twelve years ago, when Mr. 
Holden, of the Great Eastern Railway, began to use the tar 
of his oil-gas process, and found many advantages in using 
this hitherto almost unsaleable product. The success of this 
tar led him on to the use of creosote and other hydrocarbon 
by-products, and now he is using Texas oil. 

In this book the Author has endeavoured to put together 
what has been done in the burning of liquid fuel, and at the 
risk of repetition has given descriptions of various systems and 
apparatus ; and while no ' statements have been accepted 
unconsidered, he has not hesitated to use descriptions and 
statements of manufacturers in some cases with little altera- 
tion where such statements were sound and reasonable. The 
Author is not only indebted to the many whose names appear 
in the text, but also to many others who have furnished him 
with information, particularly Professor W. B. Phillips, Ph.D., 
of the University of Texas, from whose bulletins the Author 
has drawn so copiously for information on Texas oil ; to Mr. 
Thomas Urquhart, of Dalny, who, as Locomotive Superin- 
tendent of the Grazi and Tsaritsin Railway, first placed liquid 
fuel burning on a sound basis in locomotive work, and whose 
papers on the subject may be found in the Proceedings of 
the Institution of Mechanical Engineers ; to his friend Mr. 
B. H. Thwaite, whose researches in combustion have been so 
extensive. 

The work of the United States Naval Department, under 
Rear- Admiral Melville, has been so valuable that special 
appendices have been devoted to a copious abstract of the 
coal and oil tests made by the Bureau of Steam Engineering 
upon a water-tube boiler as well as tests upon the s.s. Mariposa 

The Author has also drawn liberally upon the bulletins of 
the U.S. Geological Survey for information on petroleum 
production. 

13 



14 PREFACE TO LARGER EDITION OF 1903 

To Mr. Alfred J. Allen acknowledgment is due for informa- 
tion on tar and creosote, and for tabular matter to Mr. Poole, 
whose excellent treatise on the Calorific Power of Fuels deals 
so exhaustively with coal. 

Appendices are added giving the Rules of the National 
Board of Fire Underwriters (U.S.), and also the Rules of 
Lloyd's Register of Shipping. 

Acknowledgments are due to the Electrical Review (London) 
for permission to reproduce portions of the Author's articles 
in that Journal on questions of combustion. To Mons. L. 
Bertin, of the French Navy, the Author is indebted for infor- 
mation as to the use of liquid fuel in the French Military Marine. 

The means for utilizing Liquid Fuel are very varied, yet 
all practically result in, or at least aim at, one end. It has 
been impossible within two covers to do more than select a 
number of such apparatus to illustrate the principles which 
have been followed in achieving success. The successful com- 
bustion of liquid hydrocarbon is but an extension of the prin- 
ciples necessary for bituminous or hydrocarbon coal. The 
difference is that coal is burned partly upon the grate, and air, 
to burn the hydrocarbon distillates, cannot well be introduced 
from below, as it can with liquid fuel which is burned in a 
floating condition, and can be fed with air from below very 
easily. 

The difference is but one of degree, but with liquid fuel the 
fact that all the fuel is floating, and would produce a specially 
foul black smoke under the conditions in which coal is burned, 
has compelled the adoption of means that ought to be adopted 
with coal-fired furnaces. 

The Author has endeavoured to connect the two practices, 
for in the present state of liquid fuel supply it is more than 
probable that its use will be parallel with the use of coal, 
especially in dealing with the sudden and high load peaks of 
electric stations. Liquid fuel cannot be universal unless the 
supply increases to many times what it is at present, and 
this points to a good future for the mixed system of firing, 
oil and coal being burned together in the same furnace. 

It has been difficult to make a selection of apparatus to be 
described, but the Author trusts that he has selected a suffi- 
cient number of types practically to cover the ground and 
show the general trend of practice without unduly multiplying 
examples. Indeed the tendency seems to him to be in the 
direction of one general type. As regards special boilers, oil 
does not appear to require anything more than what is re- 
quired by coal, though coal is not treated to the necessary 



PREFACE TO LARGER EDITION OF 1903 15 

appliances, and oil is so treated, and gains success where coal 
is allowed to fail. 

Much that perhaps ought to appear in such a book as this 
has been omitted, as it appears to the Author that the question 
of draught, for example, is not of the same importance with 
liquid fuel as it is with solid fuels. 

More might be said on the subject of flue-gas proportion, but 
this again has been so fully treated by other writers that it 
did not seem desirable at present to deal with it more fully. 
The most important detail of liquid fuel apparatus is the fur- 
nace and the provision of air, and of means to secure combus- 
tion and conserve temperature to enable combustion to be 
made perfect. 

Mr. Horace Allen kindly revised the section on gas analysis. 
Students of liquid fuel combustion will find enormous masses 
of information in the past volumes of the Engineer, Engineer- 
ing, and other technical papers. Much of this information 
is duplicated and historical, and the Author has found it 
necessary to ehminate almost all such matter and confine his 
space to systems now living or of recent use, or of a form recog- 
nized as useful to-day. Undoubtedly Ay don and the late 
Admiral Selwyn did much to urge the use of liquid fuel, but 
the latter injured the value of his best work by regarding 
steam as a combustible. 

The Author is also indebted to Messrs. Colonner and Lordier, 
the French engineers, for excellent information on liquid 
fuel, and indirectly no doubt to many others who are not 
directly traceable. 

Finally, his grateful acknowledgments are due to his Pub- 
lishers for the manner in which they have f acilitated his labours 
throughout. 

Westminster, 



PREFACE 

THE object of this book is to present in a bandy form tbe 
more immediate practical points of tbe Author's larger 
work on the same subject. 1 

In that book the Author endeavoured to present not merely 
the subject of liquid fuel combustion but such side issues as 
water softening, and considerably more on the general theory 
of combustion and the physical properties of materials than 
can be found room for in this present work. 

The larger work is still available for those who may desire 
the fuller presentation of the subject, but it was written at a 
time when the popular idea of liquid fuel was very hazy, and 
when the world's production of petroleum was very much less 
than it is to-day. The ideas then presented by the Author 
have since received very general acceptance. Over parts of 
the world liquid fuel will continue to take the place of coal. 
In other parts it will be used because by its means things may 
be accomplished that would not be possible with coal. This 
was amply demonstrated during the naval manoeuvres a year 
or two ago, when the stokehold crew of one of the rival fleet 
divisions were worn out and unfit for further effort. Liquid 
fuel was then resorted to and the ships simply ran away from 
the " enemy " and ravaged the south coast. 

Much of what appears in the larger work is eliminated 
because of the foregoing reasons as well as the fact that the 
subject of liquid fuel is now quite removed from controversy 
and has entered more fully upon the commercial stage, for 
liquid fuel will now be used wherever it is cheaper than coal 
or possesses circumstantial advantages which outweigh expense. 
For the peak loads of electric light supply undertakings liquid 
fuel presents itself so favourably that only surprise can be felt 
that this particular field has so far been neglected. 

This book will therefore be fairly closely confined to the 
use of liquid fuel in steam raising and in direct power produc- 
tion in the internal combustion engine. This engine has in 
the last few years made great advances and bids fair soon to 

1 Liquid Fuel and Its Combustion. Constable & Co., 1902. 

17 T* 



18 PREFACE 

find itself employed as the motive power producer in ships of 
great size and tonnage. 

While bringing up to da^e the examples of apparatus these 
have been reduced in number. Tabular matter has been 
abridged in numbers and detail and much experimental record 
has had to be cut out in order to bring the book within its 
intended compass. 

Finally it may be added that since the issue of the Author's 
larger book, there has been little change in the methods or 
apparatus employed, though there is a steady extension, 
chiefly abroad, in the uses to which liquid fuel has been put. 

The Author trusts he has given sufficient examples of 
apparatus to enable any engineer to adapt liquid fuel to his 
own conditions. He wishes to make it clear that the examples 
and illustrations are chosen as examples and are not put 
forward as being other than typical. It is not possible to 
make a book into a complete catalogue of apparatus, and 
only a few can be selected as types. 

Wm. H. BOOTH. 

38, Broad Street Avenue, E.C. 
Oct., 1911. 



There is still a big field for the use of systems of mixed 
solid and liquid fuel, as carried out notably with the Gregory 
burner described in Chapter XVIII. (June, 1921.) 



Part I 
THEORY AND PRINCIPLES 



INTRODUCTION 

THE first really practical and efficient employment of 
liquid fuel for steam-raising purposes appears to be 
due to Mr. Thomas Urquhart, of the Grazi and Tsaritzin Rail- 
way of Russia. Mr. Urquhart used the spraying system and 
obtained good results, and his paper of 1884 x marks the 
beginning of the period of really useful work. 

The application of liquid fuel in the Caucasus owes its success 
to a combination of causes. Russian petroleum has less light 
oil in its composition, and therefore produces more astatki, 
i.e. mazut or residuum ; coal is dear in the district, and the 
man was present in Mr. Urquhart to render the application of 
liquid fuel successful, previous applications not having proved 
so. 

Urquhart placed the use of liquid fuel on a sound basis. 

The Chicago Exhibition in the early nineties gave great 
impetus to the use of liquid fuel in America, for all the boilers 
there were arranged with oil fuel. only. 

In Great Britain the use of liquid fuel has not been extensive, 
but it has been marked by good practice, and only bids fair 
to become extensive since the introduction of mineral oil. 
Previously the tendency had been to use the products of distil- 
lation of coal or oil in the shape of tars or creosotes. 

To-day liquid fuel is well established and recognized as a fuel 
of extreme elasticity, and one that can be burned smokelessly. 
The days of experiment are past, and no serious difficulties 
remain to be overcome. Since 1902 liquid fuel has been 
adopted in the British Navy, and it is understood that very 
satisfactory results have been secured. 

At the same time the question must be considered from a 
conservative standpoint, because for years to come, if ever, the 
output of petroleum will not be sufficient to make it a serious 
rival of coal in every use. There is no certainty of extensive 
petroleum production in the future. Petroleum wells do not 
endure indefinitely. They are not like water wells, fed from 

1 Institution of Mechanical Engineers, Minutes of Proceedings, 1884. 

21 



22 LIQUID FUEL AND ITS APPARATUS 

surface rainfall, and geology does not assure us that thsy are 
being fed from still deeper sources, nor is it decided whether 
petroleum is of mineral or of organic origin. The future of 
petroleum is thus uncertain. 

General Considerations 

A general idea of the liquid fuel problem should therefore 
be obtained before attempting to gauge its merits. 

There is a lack of the sense of proportion in many who 
discuss the question of liquid fuel. 

In Great Britain alone over 250 million tons of coal are 
raised each year. In the United States the amount is still 
greater. The present production of mineral oil is a mere 
fraction of the millions of tons of coal produced in the world. 

Liquid fuel has undoubted advantages in many cases, and 
probably nowhere could it be used to better advantage than 
in an electric light station. 

One of the principal advantages of oil is its high calorific 
value per pound. This, with the best oils, is double the 
capacity of the inferior coals, and 30 per cent, better than the 
best coal. The ease with which it can be stored and moved 
from point to point is an advantage. It can be fired mechani- 
cally, makes no ash or clinker, can be burned at maximum rate 
or entirely turned off in a moment. Further, a very large 
power of boilers requires very little labour in the stokehold. 
Petroleum consists of a very large variety of constituents, 
gaseous, liquid, or solid. The gas is marsh gas, CH 4 , and at 
once disappears ; the lighter liquids are very volatile, and 
finally there are solid bodies at the end of a long series of 
liquids of varying degrees of volatility and specific gravity. 

The chemical formulae which cover most of the constituents 
of petroleum are C Q H 2n and CnH2 n± 2. These formulae con- 
tinue throughout the whole range from marsh gas, CH 4 , 
onwards. 

Texas oil is used chiefly as it is found. 

Russian oil is used in the form of astatki, the residuum after 
distilling off the lighting and lubricating oils. Much of the 
American oil is also used in the form of residuum. 

The proportion of carbon in all the liquids used as fuel varies 
very little from 84 per cent., the hydrogen amounting to 16 
per cent. There is little else, so that petroleum is practically 
all combustible. 

It is well established that there is at present only one way 
to burn liquid fuel for steam raising, and that is by atomizing 
the fuel in company with a sufficient amount of air around 



INTRODUCTION 23 

each atom. In order that oil may atomize freely, it should be 
deprived of viscidity by heat. Heat also causes any water 
in the oil more easily to separate out, first, because heated oil, 
being more limpid offers less resistance to the freeing of the 
water ; and secondly, there is greater expansion of oil than of 
water due to the heat, and the water gains a relatively greater 
specific gravity. 

Warming is done by a steam coil, and may be merely local 
warming in the vicinity of the take-off valve in the tank. It 
is essential that water be fairly well separated, because if it 
comes through the burners in any quantity it may extinguish 
the fires, and the next following oil is apt io ignite explosively. 

In storing oil there is always apt to be some vapour given off, 
and an empty tank ought not to be entered with a fight. 

Though not nominally of double the calorific capacity of 
average fair coal, oil is found in practice to be worth double the 
price of coal, owing to the labour cost which it saves. 

This is as regards marine service, for the oil can be carried in 
ballast tanks, and paying cargo is carried in the coal bunker 
space. 

For land purposes, these latter considerations do not weigh, 
and the relative values must be based on the performance 
ratio of about 16 to 10, together with the economy of labour, 
cleaning, ash cartage, etc. 

Above and beyond all these things, however, is the power 
which liquid fuel gives of immensely increasing the steam- 
production of a boiler at short notice. 

In general practice a steam-boiler is designed with a given 
ratio of heating surface per unit of fuel burned. Any reduction 
of this ratio is accompanied by a poorer performance. Less 
steam is produced per pound of oil consumed. A reduction of 
the heating surface ratio does not, however, reduce the per- 
formance by anything like the same ratio. 

If a large demand for steam is made upon a boiler for a short 
fraction of its working hours, it may be cheaper to consume 
fuel at a high rate for a fraction of the time than to employ 
two or even three boilers at normal rates during a fraction of 
the day, the extra boilers remaining idle during the rest of the 
day ; albeit when the heavy load is past these extra boilers 
are retired hot and full of energy. The saving by the first 
method is very considerable in respect of space occupied, build- 
ings and capital cost generally, and if not carried too far it 
will outweigh the fuel cost of the short run at heavy output. 

For this system of working, coal can, of course, be employed. 
Coal, however, cannot be fired at abnormal rates with special 



24 LIQUID FUEL AND ITS APPARATUS 

ease. A mechanical stoker does not readily increase its rate 
of working. The better forms of stoker — on the coking prin- 
ciple — cannot put their whole grate surface into the new and 
forced condition. The sprinkler class, again, do not work 
well at abnormal rates. Coal combustion is only to be regu- 
lated by draught intensity. With oil, the supply is instantly 
variable to suit the steam required, and a boiler can rapidly 
give its fullest output. With boilers of the smaller tube type 
especially, their small water contents enables the engineer to 
leave them standing cold to within a short time of maximum 
output. Oil is then turned on, and in a few minutes the boiler 
is in full work. When a boiler is already at work the mere 
turn of a handle puts it into its maximum steam-producing 
condition. 

So soon as the demand ceases the oil can be turned off, and 
the normal coal fire continued, or the boiler laid off entirely. 
By means of liquid fuel great elasticity is possible. 

In a lighting station the load factor is very usually about 12 
per cent. That is to say, about one-eighth of the plant is, on 
the average, at work all the working hours. 

This excessive misproportion is remedied to any desired extent 
by means of accumulators, but it is not yet commercially 
economical to instal so high a proportion of battery power as 
to enable the power-plant to run at steady load all day. The 
peak of the load, however short in duration, cannot be sur- 
mounted without the aid of power, and it is to the height and 
small duration of the maximum load curve that the poor load 
factor of a lighting station is due. Accumulators for heavy 
output of short duration greatly improve the load factor, but, 
in any case, the number of boilers at work to tide over the peak 
is several times the mean number. 

If, by means of liquid fuel, boilers can be heavily pushed 
for two, three, or four hours, the capital outlay on boilers will 
be much reduced. When the various points are taken into 
account, the boiler scheme that will probably suggest itself 
will be, first, some boilers of the Lancashire type, economical 
and steady steamers ; secondly, large tube boilers with a 
moderate water contents and large grate area, and with efficient 
steam driers or superheaters. These boilers can be heavily 
forced with some sacrifice of economy, but the priming due to 
heavy forcing must be ehminated by a good superheater. This 
is essential to economy. Thirdly, small tube boilers of very 
small water capacity, capable of being heavily forced, delivering 
their steam preferably above water level in the steam drum. 
If all these boilers are fitted with oil sprayers, the maximum 



INTRODUCTION 25 

demand for steam will be met with the minimum of capital 
outlay. 

It is a fallacy to suppose that boilers of small water capacity 
respond most readily to a sudden demand for steam. 

When a boiler is at work under full pressure, the whole of its 
water is at a temperature which corresponds with the pressure. 
Any addition to the furnace activity cannot add to the heat 
contents of the boiler, unless the pressure is allowed to rise ; 
obviously, therefrom, given the continuance of the same pres- 
sure, the boilers of large water contents will answer to an urged 
fire just as rapidly as a boiler of small water contents. When 
boilers are standing at rest, however, and cold, the boiler which 
contains the least water will, ceteris paribus, become most 
quickly hot. Such a boiler as the Solignac, which holds almost 
no water, can be made, by aid of oil fuel, to produce its maxi- 
mum power in a few minutes after lighting up. 

In this respect oil has a decided advantage over solid fuel. 
To secure a good fire with solid fuel there must be a thick bed 
of incandescent fuel on the grate, and this can only be built 
up with comparative slowness, and when its duty is over it 
remains a more or less wasted force. With oil, however, the 
maximum fire is instantaneous, and the only drawback is the 
cold brickwork of the setting, which must become hot before 
the maximum furnace duty is attained. 

For ordinary economical work the number of heat units that 
a boiler can absorb per square foot of heating surface will not 
be changed when liquid fuel is employed, except so far as liquid 
fuel can be burned without smoke more easily than can solid 
hydrocarbons, such as coal, and thereby the heating surface 
is maintained clean and free from dust and soot, and more 
efficient. Evaporative efficiency must not be allowed to out- 
weigh the overall, or commercial, efficiency. Exactly what 
governs the relation between evaporative and commercial 
efficiency cannot be stated positively. Indeed, commercial 
efficiency alone should be considered as the true basis of design. 
It may, however, be stated in general terms that plant which 
is on duty for long hours may be designed to work more economi- 
cally as regards fuel than plant intended to work very short 
hours. 

Let it be assumed that the boilers which are economical of 
fuel have an efficiency of 72 per cent., and that the small highly 
pushed boilers are run at 60 per cent, efficiency for three hours. 

Then, in course of a year, fuel is wasted which represents 12 
per cent, difference of efficiency lost for three hours daily. 
To enable this loss to be avoided there would be so many 



26 LIQUID FUEL AND ITS APPARATUS 

thousands of pounds extra capital cost in boilers, buildings, 
etc., and where oil is not employed, so much more labour cost 
as compared with oil. Properly equated at a suitable rate of 
interest and depreciation, the relative value of the alternative 
systems may be found after the manner of the Kelvin law 
applied to cable work. In many stations the extra labour 
for the heavy duty period is difficult to arrange satisfactorily. 
Men are employed more hours than they really work, and where 
it may be best to use coal for 10 hours, the labour cost may 
make it cheaper to use oil for 4 hours of a peak load, even if, 
in mere fuel cost per unit, the oil is more expensive. 

Trials with liquid fuel show that there is still much to be 
done in reducing the air supply. The air required to burn 1 
unit weight of carbon is 11 J units. An ordinary oil fuel re- 
quires fully 15 units, with, of course, some additional excess 
as with solid fuel. But with oil fuel there ought to be better 
mixture of air and fuel, and therefore better combustion with 
less excess of air. 

If we regard air as the fuel and coal or oil as the sustainer of 
combustion, as we have a chemical right to do, we shall arrive at 
the conclusion that, approximately, the calorific value of a fuel 
in actual duty done will not differ much from the chemical 
ratio of air required in the combustion process. The large 
amount of air per pound of oil arises from the large percentage 
of hydrogen in the oil, and it is the large capacity for oxygen 
possessed by hydrogen which renders the theoretical tem- 
perature of combustion so nearly like that of carbon, in spite 
of the high calorific capacity of hydrogen. 

As regards the production of petroleum, that of the United 
States in the year 1901 was 69,389,194 barrels, valued at 66 J 
million dollars. If each barrel is assumed to contain 360 lb., 
or say 6 barrels per ton, the total tonnage will be 11,565,000, 
and the value, therefore, something under 235. per ton, or prac- 
tically $1 per barrel. Thus the weight of oil produced in the 
United States was about 5 per cent, of the weight of coal, or 
say 7J per cent, of the calorific capacity. After the removal 
of the fighting and lubricating oils, the amount of fuel oil 
remaining was quite small as compared with the coal output. 
It may be assumed that the total oil production of the world 
is not 5 per cent. 1 of its coal production. Any idea of 
entirely displacing the coal must be out of the question, unless 
the yield of oil be increased beyond present prospects, and the 
use of fuel must therefore be undertaken with common-sense 

1 1921. The ratio is now about 10 per cent. 



INTRODUCTION 27 

caution, and not in any wholesale manner, to the expected 
exclusion of coal. 

At the same time, when the limitations of the subject are 
recognized, it cannot be denied that liquid fuel lends itself to 
certain ♦conditions as to steam raising which must render it 
extremely valuable and of great convenience. Marine work 
and electrical work are, par excellence, the two lines along 
which liquid fuel appears likely to advance most successfully, 
and in the author's opinion steam-driven motor cars may 
eventually discard the dearer oils and employ the heavy oils 
and residuum as fuel by means of atomizers. According to 
present appearances, the motor car or tractor offers one of the 
finest fields for the use of the heavy fuel oils, as distinguished 
from the petrols or even the cheap lamp oils, such as are already 
used on steam cars. Little has yet been done in this direction. 
It may, however, be added that the commoner grades of para- 
ffine are at present so cheap that such vehicles as steam omni- 
buses are not tempted to depart from paraffine in favour of 
heavier oils. Such cheapness appears to arise from fighting 
competition, and if so will not last. 

1921. Much was done quietly during the war by way of 
introducing liquid fuel throughout the Navy. The pressure- 
jet syste:n of atomization by high pressure came well to the 
front. This atomization through small whirl passages of 
course demands good heating and filtration and it is about 
10 per cent, superior in economy to air or steam systems. 

As an example of what oil will do may be cited the case 
of a 6,000 i.h.p. destroyer of 30 knots and 350 tons, which 
burned 139 pounds of coal per 100 ton-miles, whereas a later 
34-knot boat of 800 tons and nearly 18,000 i.h.p. burned only 
83 pounds of oil per 100-ton miles. More duty per ton-mile 
is of course to be expected in a bigger vessel, but the com- 
parison is notable. In the U.S. Navy oil and coal have been 
founl to have a relative evaporation of 14*45 and 9-31. 



CHAPTER I 



THE GEOLOGY OF PETKOLEUM 



IN this book very short reference only is needed to the sub- 
ject of the Geology of Petroleum and the method of 
procuring it. 

Petroleum is found in various geological formations, from 
the Silurian and Carboniferous in the United States, to the 
Tertiaries in the eastern hemisphere. It indicates its presence 
sometimes by the escape of inflammable gas at the surface, 
sometimes by the existence of deposits of pitch or asphaltum, 
as at La Brea in Trinidad, where a large lake of pitch has been 
recently proved to have indicated petroleum below. Some- 
times petroleum oozes from surface outcrops. Where there 
are no surface indications petroleum may be inferred to exist 
where the geological conditions resemble those of known and 
proved fields. But no geological knowledge can go beyond 
this. In a proved field there is greater certainty of success 
along any particular line of country with each successful boring 
that has been made along that line. 

Petroleum is very usually found to lie along an anticlinal 
fold, more or less inclined, the oil having been forced into 
such ridged or domed formations by the superior gravity of 
water pressure behind it. A natural sequence of this is that, 
when an oil well becomes exhausted, the oil is frequently 
succeeded by a flow of water — often salt. 

This frequent presence of salt water with petroleum lends 
colour to the supposition that petroleum is of marine origin, 
and formed by the action of heat and pressure on marine 
organisms of animal or vegetable origin. 

Porous strata are the most favourable for the storage of oil 
owing to their porosity. When overlaid by impermeable beds 
of clay, gas usually accompanies the oil when first struck. 
When oil occurs in clay, as in the oil shales of Scotland and of 
New South Wales and in the Kimeridge Clay of England, the 
clay has merely absorbed the oil and holds but a comparatively 
small quantity. The gas has often escaped. At Heathfield in 



THE GEOLOGY OF PETROLEUM 29 

Sussex the author bored a well in 1896 for the London and 
Brighton Railway Co., upon an anticlinal fold of the Weald. 
Very little water was found, but gas at considerable pressure 
had been enclosed by the impermeable dome, and has since 
been used to light the Company's station. But the oil with 
which it is associated is probably only that small amount which 
was proved by the subwealden boring in Limekiln Wood, 
near Battle, and has long been known to be contained in the 
Kimeridge Clay which has for years been worked for oil at 
Wareham in Dorsetshire. 

Surprise is sometimes expressed that within a small distance 
of each other some borings yield good supplies of oil, while 
others close by are barren. But we cannot know the hidden 
geology of any area, even if the surrounding outcrops appear 
to point to continuity and conformity. Thus who was to 
know, until the classical bore-hole was made at Meux's brewery 
in Tottenham Court Road, London, that when the lower 
Greensand was being deposited in a salt sea the site of London 
was an uprising above sea level of a mound or ridge of Devonian 
rock, so that the greensand Sea extended only to a point under 
the above brewery. Take the map of Ireland and look at the 
deep indentations of the south-west coast, Bantry Bay, Dingle 
Bay, the Kenmare River and Dunmanus Bay. Imagine this 
area gradually to sink deep below sea level and to be wholly 
covered with clay. Then according as a bore-hole was put 
down from the surface above what is now hard rock, or above 
what is now the sea, so would the thickness of the surface 
stratum of clay vary by many hundred feet. The cliffs being 
vertical in places, this difference of thickness might occur in a 
distance of a few feet. A fault would possibly be declared to 
exist, whereas the difference would merely be due to the ancient 
marine action, which has left standing these upturned hard 
rocks whose synclinal folds may have an equal dip below the 
waves that the anticlinal folds have a rise above them. Such 
natural features as appear in present day surface geology may 
be fairly assumed to have formed the ancient floor on which 
more recent strata have since been deposited. 

The presence of oil in any stratum does not necessarily in- 
dicate that it was formed in that stratum. It may have found 
its way there by reason of the superincumbent pressure of the 
overlying strata, or it may have reached such stratum vaporized 
by heat and there condensed to liquid. Or again, it may have 
been forced to leave some earlier location, no matter how it 
reached such earlier location, by the superior pressure of water. 
Water indeed has much to do with what, for lack of a better 



30 LIQUID FUEL AND ITS APPARATUS 

term, may be called the hydrogeology of petroleum. When a 
petroleum well gushes, it does so because the oil is being pressed 
upon by water, which, but for the presence of oil, would itself 
rise near to or above the surface. 

A case may be pictured, as in Fig 0, where a porous stratum m 
is fed with water from the surface at S. This water escapes 
by some opening to the surface, or it may flow away in the 
direction of c to some surface spring at the level of the water 
line marked W.L.I. 

In the anticlinal fold or dome under the point A there would 
be a reservoir of oil under a water pressure equal to P. A bore- 
hole at A, right above the ridge of this buried anticline, would 




Fig. 0. — Hypothetical Section of Oil-bearing Stratification. 

allow this pool of oil to escape at the surface as a gusher. 
And when all the oil had escaped the well would yield water. 

Similarly a boring at B would yield oil equally freely, but 
water would follow while still the crown of the dome contained 
oil above the upper dotted line. A well at G would yield 
water from the first, while at D neither oil nor water would be 
found unless the bore-hole was carried down below W.L.I. 

Let all the conditions remain the same, except that the water 
level stands at the line W.L.2. The same results would happen, 
except that the wells would not yield above the surface. They 
would be known as pumping or baling wells. The hole D 
would pass through the water-bearing stratum on to the left of 
the water level, and would therefore be dry. It is easy to 
multiply these assumed geological forms in order to account for 
every peculiarity that may be met with. 

Readers can picture for themselves the very much wider 
fields over which boring would be successful if the water only 



THE GEOLOGY OF PETROLEUM 31 

stood at W.L.3, for with suitable stratification to the right of 
c, it would be possible for oil to fill the stratum m even to the 
surface, and the whole of the oil could be finally baled, and 
without meeting with water. Nor is it necessary to assume the 
existence of a buried anticlinal. A mere frustrum may alone 
have been left by surface denudation and borings along the 
side slopes of this frustrum may reach oil. But a gushing well 
demands artesian pressure or gas as its acting force. 

The boring of an oil well is complicated by the occurrence 
of water-bearing strata above the oil-bearing stratum, and it 
is possible to let down this upper water into the oil stratum 
below in such a way as to force away the oil and render 
large areas barren of oil. Hence the extreme importance of 
shutting out such water by casing tubes tightly inserted. 

Thus if n was a water-bearing stratum the casing pipe must 
pass through this and enter well into an impermeable stratum 
below, such as let it be supposed i may be. 

Where the slopes of an anticline are steeply inclined the oil 
fields will be very narrow, and this explains the closely spaced 
derricks seen on some fields extended in a narrow line along 
the anticlinal ridge. Every bore-hole that is put down affords 
figures from which the underground contour of the rocks can 
gradually be worked up, and plots of land gain or lose in value 
as it becomes easier to make definite statements as to the depth 
to the oil stratum and the certainty of being to the left or right 
of points, such as e, on which yield depends. An inspection 
of Fig. 1 will serve to show how easy it may be to drive casing 
so as to shut off a supply of oil, and how it might also happen 
that instead of oil, water would be obtained. It is also clear 
that a well may cease to yield oil sooner than it would do if the 
casing had not been driven too far. Thus a well that has 
ceased to yield might, on occasion, be again brought in by 
perforating the casing at a suitable horizon. 

Any attempt to prove oil or find it without some surface 
indication is considered to be speculative or of a " wild cat " 
order. But there can be very little doubt that great deposits 
of oil are lying hidden beneath rocks which are completely 
shut down below superincumbent strata and have no outlet 
to the surface by which they can give the faintest indication 
of their presence. Oil exploitation so far has been carried out 
on the lines of working coal seams from their outcrop only. 
Coal is a regular geological stratum, and its presence may be 
inferred at long distances from any outcrop, as it was inferred 
at Dover as a result of the artesian boring in Tottenham Court 
Road. But oil is not a geological positive fact, for it may be 



32 LIQUID FUEL AND ITS APPARATUS 

found to-day far from its point of formation, as stated above, 
having suffered lateral or vertical transfer by the agencies of 
heat, water, gas or gravity. It is therefore liable to be found 
in strata of all geological periods . If present in Great Britain in 
serious quantity it is probable that it will only be found at very 
great depths. Very little is known of the deep-seated rocks 
of Britain below the coal measures, and the deepest coal mine 
is not much over half a mile. But the recent strata of the south- 
east of England are now known to lie unexpectedly and uncon- 
f ormably upon ancient rocks of Devonian and Silurian and also 
Carboniferous age. So that the unexpected may yet happen 
in the shape of a petroleum field in Great Britain, possibly 
in the deep-seated Old Red Series which are known to yield 
salt water and suspectedly petroliferous. 



Petroleum Drilling and Pumping 

Oil wells are bored by the aid of a derrick about 50 to 80 
feet in height ; 72 feet being a very usual height. A derrick is 
built up of four stout inclined corner posts, braced by horizon- 
tal struts and diagonals. Many modern derricks are of steel. 

The tool usually employed is a heavy chisel attached to a 
heavy sinker bar. Sinker bars vary in size from 2| inches 
square by 30 feet long up to 7" x 15 feet. They are raised and 
lowered, by a rope or by a line of iron rods or poles. A rapid 
up and down stroke is given by means of a walking beam to 
which the rope or rods are attached by a long screw frame or 
temper screw, or by a chain from a winch carried on the beam 
itself. The rope is let out by turning the temper screw as the 
chisel cuts the rock and the rods are lowered gradually by the 
winch. Debris is removed by drawing up the line of tools and 
lowering the sand pump or shell, — a long tube with a valve at 
its foot, by means of a winch and rope over a pulley at the 
top of the derrick. The walking beam and the winch barrel 
are set in motion by means of belts from pulleys on shafts 
driven by an engine, such belts being slack, but tightened up 
to working tension by pressure from lever-actuated jockey 
pulleys. Other levers control the band brakes which hold the 
mechanism securely at rest when needed. A second winch 
raises and lowers the casing tubes. In Russia wells may start 
with casing as big as 24 or 36 inches diameter. In America 
wells are usually 8 and 10 inches, finishing as small as 4 inches. 

Another system of boring is the rotary system, by which the 
casing itself forms the tool and is rotated by gearing at the 



THE GEOLOGY OF PETROLEUM 33 

surface and sinks through loose strata by the aid of a flush of 
water forced down the casing, and escaping into the strata 
through which the casing penetrates, or making its way to the 
surface outside the pipe. 

Boring operations are simple while things go well, but ropes 
and rods break, the bore-hole walls fall in, the chisel is jammed 
fast or the casing collapses under heavy pressure from without, 
and a great variety of salvage or fishing tools are made to combat 
these contingencies. Hence the need for strength and the 
reliability given by Low-moor orFarnley iron for special items. 

Owing to the inflammability of the gas and oil which a well 
may yield, the boiler is kept well back from the derrick, and the 
engine is connected by a long belt to the mechanism of the rig. 

Derricks are now frequently formed entirely of steel. 

Casing consists of lengths of steel pipe screwed to a butt 
joint and socketed. They are used in random lengths, unlike 
the English artesian system of using dead lengths of 10 or 12 
feet, which render it so much easier to know the exact depths 
to which casing has been driven. 

When oil has been obtained, but does not flow to the surface, 
it is raised by the baler, a long pipe with a valve at its base, 
which is lowered by a winch and rope into the oil and hauled 
up full of oil. Baling may be continuous night and day at maxi- 
mum possible yield, or, if supplies are poor, baling will be done 
morning and evening for as long as desirable, the oil accumulat- 
ing in the day and night between baling times. 

Or pumps may be employed, and on some fields many pumps 
are worked from one central engine by means of a crank rotat- 
ing on a vertical spindle and hauling upon a number of tension 
ropes attached to the pumps like spokes radiating from a central 
hub. When the oil is not too deep below surface the air lift 
pump may be employed, though this is expensive to work, owing 
to the general low efficiency of compressed air, but it has some 
very serious advantages. 

Given that the oil is present in a well, more can be raised by 
the air lift in a given time than by any other system. This is 
specially valuable where there is a free supply of oil and the 
well is of small diameter. 

There are no moving parts down the well. Any number of 
wells can be pumped from a single power station, the compressed 
air being carried to each well by a branch from an air main. 

The central power station may be at any distance from the 
wells, so avoiding all risk of fire. 

Oil containing sand can be raised with ease. Sand causes a 
good deal of wear in pumps. Both pumps and balers can be 

c 



34 LIQUID FUEL AND ITS APPARATUS 

worked with safety by enclosed electric motors, the current 
being brought from a safely distant power-generating station. 

In using boring systems which involve the employment of 
water flushing for debris removal, there is risk in some circum- 
stances that the oil when reached may be driven away by the 
water flush and passed by without its presence being suspected. 
Engineers should always be alive to this danger. 

Diamond rotary drilling is not employed for oil drilling, for 
the " crowns " become two expensive for the size of holes 
required to be drilled. 

Hard rocks may be easily penetrated by the rotary process 
with chilled steel shot. But this system requires a flush of 
water with its possible disadvantages. The ordinary method 
with heavy crushing chisel has the very serious disadvantage 
that it smashes everything to a pulp, and destroys the best of 
the fossil evidences of the rocks passed through. 



CHAPTER II 

THE ECONOMIES OE LIQUID EUEL 

IN considering the application of liquid fuel every case 
must be taken by itself and the costs evaluated. In 
favour of oil there is, first, the ease and rapidity with which 
a liquid can be taken into store and delivered to the bunkers 
of a ship or the tank of a locomotive. Next there is the 
economy of labour, which may be almost nil in case of a single 
boiler with one attendant to the engine and boiler, or it may 
be very great where there are many boilers. 

The superior calorific power of oil must then be equated 
with the price, and the cost per unit of evaporation found from 
this. 

The removal of cinders and ash may or may not be a matter 
of cost, according to the demand for them locally. 

Liquid fuel possesses great elasticity of use and fits well 
with sudden and varied demands for power. Hence its value 
in railroad work, electric light work, and other power stations 
where loads vary greatly. 

Where the mixed system is employed, as with the Great 
Eastern Railway, the mere question of economy, as based on 
the actual weight of fuel consumed, is to be found as follows : 

A locomotive consumes N units of coal per unit distance. 
When running with coal and oil, it is found to consume 
M units of coal. 
„ „ oil. 
The price of coal is y ; of oil x per unit. 

Then Ox mo +Mxy - N x m>' orx£ iy( N ~ M )- 

The cost of oil is largely a matter of carriage. What costs 
three francs = 2s. 6d. per ton at Baku costs 185 francs = 
£7 8s. 6d. in France. The difference of 182 francs is made up 
of railway and sea carriage, handling, customs, warehousing. 
The customs stand for ninety francs, so that the same oil at 
an English port should not cost over £3 16s. 

35 



36 LIQUID FUEL AND ITS APPARATUS 

American residues cost five to six francs more than Russian 
mazut, whence MM. Colonner and Lordier, who give the above 
figures, dismiss oil as an economical fuel in France pending the 
reduction of the tariff. 

On the Southern Pacific Railroad the relative evapora- 
tion of oil and coal is 365 : 274, or 33 per cent, in favour of 
oil. 

On the International and Great Northern four barrels of oil 
proved more than equal to a ton of coal, and at 125. 6d. per 
ton and 2s. 4d. per barrel the economy of oil was 13 to 14 per 
cf it., including the economy of handling and storing. 

To produce 1,000 units of steam, coal gives out more carbonic 
acid than oil, though the oil destroys quite as much oxygen 
and reduces the life-supporting power of the air to probably 
equal extent. So long as combustion is perfect and no actual 
poisons are made, there is not much to choose between the 
two fuels beyond their sulphur contents. As regards the 
safety of oil, it has been shown that oil with 117°C. = 239°F. 
flash-point did not ignite if fired at with shell, nor did 
dynamite exploded in a reservoir of this oil do more than throw 
up jets of oil which did not ignite. 

Any danger with liquid fuels is with the oils which have not 
parted with their inflammable and volatile gases. This is a 
danger with oils when used absolutely crude. Purged of 
these portions, however, oil is safe, and, moreover, unlike coal, 
it contains no power of spontaneous combustion. Though 
it is claimed by some that oil does not deteriorate if kept in 
tanks, others do claim that a certain deterioration is produced 
which renders it difficult to atomize, the oil becoming more 
thick and viscid. 

In Russia circular atomizers are often employed which give 
out a large hollow flame. The Bereznef atomizer, is one of 
these. They have the disadvantage of being out of reach in 
the middle of the fire of a locomotive, and they become burned 
also through being in such close contact with the flame. 

Steam enters below a central disc, and oil flows under a 
head of two to three metres on the upper side of the disc. 

The advantage of this form is said to be its constant out- 
put. 

Too much mazut produces smoke, too much steam is waste- 
ful. There is a certain fixed ratio of oil and steam to give the 
best result. The Issai'ef atomizer, which resembles the Berez- 
nef, will feed 50 to 100 kilos, of oil per hour (110 to 220 lb.), 
and it consumes nearly 0-4 kilos. = 88 lb. of steam at 4 to 5 
atmospheres pressure per kilo, of oil (2-2 lb.). The table, 



THE ECONOMIES OF LIQUID FUEL 



37 







NO 


. OF TEST. 




DATA. 


l 


2 


3 


4 


5 




3 atomizers 


4 atomizers 


1 atomizer 


3 atomizers 


3 atomizers 




Bereznef 


Kroupka 


Bereznef 


Bereznef 


Baschinino 


Duration of trial. Hours . 


12hrs. 


lOh 30m. 


lOh 30m. 


7 hrs. 


9 hrs. 


Total kilos, of oil consumed. 


2193 k. 


795-7 


1,104 


1,183 


1,183 


Mean boiler pressures in at- 












mospheres 


4-5 


50 


4-5 


50 


4-75 


Mean temperature of feed 












water 


41°C. 


38°C. 


46 6°C. 


19 2°C. 


20- 2° C. 


Litres of water fed to boilers 


31,096 


11,912 


16,232 


16,284 


16,832 


Kilograms of water fed to 










B . 


boilers 


29,140 


11,122 


15,071 


15,805 


16,310 


Kilograms of steam produced 












at feed temperature per 












kilo, of oil 


1417 


14 9 


14-7 


13-76 


14-22 


Kilograms of steam produced 












from 0°C. per kilo, of oil . 


13-28 


139 


1365 


13-36 


13-78 


Oil per hour per square metre 












of grate surface. Kilos. . 


0-987 


1-131 


1-569 


1-469 


1-143 


Steam per hour per square 












metre of grate surface. 












Kilos 


131 


15-81 


21-42 


19-633 


15-758 


Tempera- (of feed water . 
ture j of chimney gas . 


120°C. 


85° 


87-3° 


68-9° 


64-6° 


132°C. 


130° 


139-1° 


90° 


80° 


(of air above boilers 


2 7° C. 


27° 


20° 


27° 


26-8° 


Atomizing steam per kilo of 












oil. Kilos 





422 


0-364 


— 


— 


Heating surface. Sq. metres 


185 


60 


60 


115 


115 



= 10-76 square feet. Kilograms ] 
= pounds per square foot nearly. 



)er 



square metre 



above, is given by M. Keller, of Moscow, as the result of 
tests made with various atomizers. 

M. Bertin, in dealing with the efficiency of liquid fuels, 
points out that a fuel containing 85 per cent, of carbon and 
14 per cent, of hydrogen, will consume the oxygen of 7-56 
cubic metres of air to satisfy the carbon, and of 2-72 metres to 
satisfy the hydrogen, or 10-28 cubic metres in all. By adding 
40 per cent, excess of air, or 14-4 cubic metres =18-7 kilos, 
of air per kilo, of oil, then combustion will be perfect and 
smokeless. 

The Author's own figure for the weight of air chemically 
necessary for the above sample would be 14-7 nearly, and 40 
per cent, excess would increase this to 20-56. M. Bertin's 
figure of 18-7 appears to represent about 27 per cent, air excess. 

The theoretical temperature of combustion will be — 

(T8^f^23 = 2 ' 480OC -= 4 ' 496 ° F - 



38 LIQUID FUEL AND ITS APPARATUS 

If the gases leave the boiler at 300°C. = 572°F. the loss of 
heat will be -^—— = 12-10 per cent, of the total, which is equi- 
valent to an increased efficiency of 6- 65 per cent, as compared 
with coal. He further estimates a gain of 1-9 per cent, over 
coal in the absence of ashes and their cooling (onboard ships). 

The efficiency of a boiler estimted at 75 per cent, for coal, 
becomes 0-835 for oil firing, or 0-75 + 0-0665 + 0-019 = 
0-835. 

But good combustion and utilization still further favour oil 

•835 
in the ratio- = 1-28 — m ; m becoming then r — 1-20 X 

• DO 

1*28 = 1-53 ; the figure 1-20 being the chemical ratio of power 
of coal and oil. In Torpedo-boat No. 62 (French) M. Bertin, 
however, only obtained m = 111 and r = 1*33. The causes 
of the difference are found in the nature of the flame of oil, 
which has less radiating power than the flame of coal, and the 
powerful effect of the directly heated coal furnace is sacrificed, 
and to secure the same results an undesirable extension of heat- 
ing surface would be necessary. 

Secondly, the flame of oil is long if care be not taken suitably 
to arrange the burners. It may pass between the tubes and 
become extinguished, and the gases partly burned may even 
relight in the chimney. The chemical action and reactions of a 
burning spray of oil may be very much complicated by disso- 
ciation or even by exothermic formations, which may delay 
heat production. Later when combustion becomes active as 
shown by the light giving power of the flames, it will be more or 
less rapid according to the perfection of air admixture, and will 
last for a time = t, during which the jet, travelling at a high 
velocity, v, passes through a distance L = vt, which may be 
yards in length. 

Thus the course of the gas must be long, or it may escape too 
hot to the chimney. Hence arises the necessity of cutting short 
the flame by early admixture and high temperature, so as not 
to lose the benefit of the boiler-heating surface. 

It is for this purpose that in most successful oil-burning fur- 
naces the jet of atomized oil is directed upon a brick obstruction 
of some kind so as to spread the flames and cause them to fill 
the furnace space and lick round the plate surface. Locomotive 
fireboxes may be studied, as in Fig. 26 to show how this effect is 
secured before the gases escape to the small tubes. 

General Prinicples of Liquid Combustion. — A review of the 



THE ECONOMIES OF LIQUID FUEL 39 

whole subject, in the light of chemical knowledge, of the claims 
of manufacturers and of users of liquid fuel, shows that success- 
fully to burn a liquid it must be finely pulverized, to do which 
it must be heated sufficiently to destroy its viscosity and en- 
able the spraying agent, air or steam, to tear it up and disperse 
it in a fine spray intimately mixed with air. The correct 
amount of air must be admitted to burn the liquid, and this is 
one of the advantages of employing air as the atomizing agent. 
Where sufficient air cannot be introduced with the fuel, it 
must be admitted from below, as through grate bars covered with 
broken bricks. Steam, preferably superheated, is the most 
convenient to employ as the atomizing agent, but on the salt 
seas has the disadvantage of wasting from 3 to 5 per cent, 
of the steam made by the boilers, and this loss must be made 
good by evaporators. 

As with bituminous coal, which, like oil, is a complex 
hydrocarbon, liquid fuel should be burned in furnaces more 
or less protected from immediate loss of heat to the boiler 
surfaces by means of linings or baffles of firebrick. Liquid 
fuel, however, is more easy to burn completely than is coal, 
because it can be more intimately mixed with the necessary 
air. The interior of a combustion chamber should show a 
clear white incandescence with little apparent flame, and no 
smoke or unburned gases coming from the chimney. If looked 
into through a piece of violet-coloured glass, the interior of the 
combustion chamber with its brick linings should show a light 
lavender colour indicative of perfect combustion, with the pro- 
duction of actinic rays indicative of high chemical action. A 
chilled fire, such as is produced where a boiler is placed close 
upon the furnace of a coal fire, will show very little light indeed 
through a violet glass, its flames being cut down from several 
feet in length to a few inches only in many instances, the flames 
of yellow and reddish intensity being resolved into streams of 
dun-coloured gas which throw off no light of sufficient actinic 
power to penetrate the glass. 

Much difference of opinion exists in regard to the flash-point 
of the oil to be used. Crude oil is so widely different a product, 
according as it comes from one or another locality, that no rule 
can be laid down as to its safety or otherwise. Those crude 
oils which, like the Pennsylvania oil, give a large proportion 
of gasolene and other volatile compounds, are not used in their 
crude form because they pay better to refine, the heavier resi- 
duum being used as fuel and being much safer. The use of 
volatile liquids is only undesirable on the score of safety. 
Some of the crude oils, as for example those of the Beaumont 



40 LIQUID FUEL AND ITS APPARATUS 

field of Texas, contain so little of the lighter oils that they are 
used as fuel in their crude form. The one thing to note is that 
the more highly volatile oils have an element of danger from 
which the heavy oils are free, and this danger intensifies the 
results of every possible accident that may occur, especially such 
as arise from rupture of an overhead tank and the gravitation 
of the oil to lower points. The whole question is really very 
simple, and resolves itself into an intimate mixture with air in 
sufficient quantity and a proper conservation of the temperature 
pending full combustion. Fortunately for liquid fuels, these 
items are not only easy to realize, but failure, when they are 
not realized, is far more disastrous and complete than in the 
case of solid fuels. Hence the really simple problem of burning 
bituminous coal has never been properly solved, except in a few 
cases. At the same time it is easy of solution, but if not solved 
it does not produce the same bad effects as does the faulty com- 
bustion of liquid fuel. In regard to this question, the Author 
would like to point out that, where coal is burned in a refractory 
furnace, it should be capable of burning perfectly, with less 
excess of air, and coal ought to give results more nearly ap- 
proaching its true value than it does do in ordinary faulty 
daily practice. Probably all the comparisons given in this 
book, except, perhaps to some extent those of locomotives, 
are too favourable to liquid fuel, which is supplied with those 
essentials of perfect combustion that are withheld from coal. 

This question of refractory linings is essential, and it is 
secured by bridge walls, overarching and, where fire-bars are 
left in place, by covering these with broken firebrick or by whole 
bricks laid on edge. 

It does not seem possible to introduce all the necessary air 
with the fuel. A chemical minimum of fifteen pounds of air 
is necessary to supply the oxygen for the average hydrocarbon 
liquids, but probably at least 5 to 10 per cent, excess is required 
in the best practice, and this must come in below the oil spray, 
and should not be introduced in a single large stream, but 
divided up into numerous fine streams through perforated plates, 
or through a mass of broken bricks or loosely laid brickwork. 
In Fig. 51 is shown the arrangements of air admission at the 
floor of a water- tube boiler furnace which is in the right direc- 
tion. The Weir boiler, Fig. 7, p. 121 is also suitably arranged 
for liquid fuel, as regards the lining of the furnace and combus- 
tion-chamber. Where liquid fuel is used alone the fire-grate 
would be covered with bricks laid on edge or simply broken into 
pieces of 2-inch cubes, and the atomizers would be arranged 
similarly to those of Fig. 51. The general conditions that have 



THE ECONOMIES OF LIQUID FUEL 41 

been evolved are well shown in the various locomotive and 
stationary boiler furnaces illustrated in Part II. 

In the Weir small water-tube boiler the sides of the /y-shape 
furnace are lined in firebrick blocks which are threaded upon 
the middle widely spaced tubes which form the walls of the 
furnace proper. 

The first row of the main body of tubes is similarly protected 
to form a refractory wall for the combustion chamber. Thus 
both the furnace and combustion-chamber are fully refractory 
on two sides. Such a boiler as this can be worked with coal 
entirely, with oil alone, or upon the mixed system, the brick 
finings enabling combustion to be carried out with smokeless 
and economical perfection. 

By means of sight-holes the furnace can be examined, and the 
admission of air gradually increased until the gases become 
clear, clean, brightly incandescent red, and the opposite end of 
the furnace shows up clearly. So long as there is smoke-forma- 
tion the opposite brickwork cannot be seen. As soon as com- 
bustion is perfect it appears clear and bright red, and the air 
should then be cut down in quantity until an occasional streak 
of dark-coloured gas begins to show, thus proving that under 
the conditions of the furnace the air has been reduced to a 
possible minimum. 

Under some conditions of boilers it would appear that to 
ensure smokeless combustion of liquid fuel, not more than 2 to 
3 lb. should be consumed per hour per cubic foot of combustion 
space. This will have considerable bearing upon the question of 
furnaces with or without fire-grates, the latter type more easily 
securing the requisite volume. The above figure may be borne 
in mind when considering the question of furnace dimensions. 
More recent practice is claimed to give a nearly smokeless com- 
bustion with a rate of 20 lb. of oil per cubic foot per hour. 

The term liquid fuel is herein limited to — 

1. Coal gas tar, creosote, coke oven tars, blast furnace tars, 

and the tar from oil gas manufacture and other pro- 
ducts of the destructive distillation of fuels, including 
the more volatile naphthas. 

2. Petroleum and other mineral oils found liquid in nature or 

distilled from bituminous shales. 

In a work of this nature, also, it would not be possible to 
take notice of all the uses of liquid fuels. For the purposes 
of this book, therefore, liquid fuel includes the products under 
sections 1 and 2 which do not possess a volatility or refinement 
greater than those of the heavy paraffin series or fighting oils. 

The crude mineral oils of course contain such volatile consti- 



42 LIQUID FUEL AND ITS APPARATUS 

tuents, and may be used in their crude form, but usually the 
superior value of the distillates leads to these being first sepa- 
ated, the coarse residuum known as astatki or mazut being the 
oil so much used as fuel. Having been deprived of its more 
volatile portions, it is safer to carry and to use. 

A liquid will not burn when cold, and cannot be ignited in 
mass. If heated to the point of ebullition and supplied with 
air, it will of course burn fiercely and uncontrollably. The 
art of burning liquid fuel consists in heating only the portion 
which is to be immediately burned and exposing it to contact 
with air. Unlike coal, it is not possible to burn it at many sur- 
faces. A coal fire is made up of many pieces of coal, each burn- 
ing over its whole surface. Liquid fuel will not lie on a grate in 
separate pieces. If, however, a layer of liquid were heated to 
vaporizing point, or nearly so, on a finely perforated plate, 
and highly heated air were forced through the perforations, the 
liquid would no doubt burn freely with strong flame, but the 
mass of heated liquid would be difficult to control. Hence in 
practice we arrive at those systems which employ a jet of air or 
steam to split up a stream of liquid into fine globules in presence 
of a sufficient supply to air. Each globule burns superficially 
and becomes heated by its own combustion and the general 
heat of the furnace, and this principle appears to be the best 
and most effective method of burning liquids. Indeed, it is 
perhaps the best method of burning anything, first to reduce 
it into particles so fine that their bulk bears a small ratio to 
their surface area, whereby each particle is brought close to the 
air which it requires. 

Atomizing. 

The necessity for atomizing arises purely from the insufficient 
surface area of the fuel otherwise treated. A fire composed of 
lumps of coal is full of interstices, and the area of the fuel ex- 
posed to air is much greater than the area of the fire-grate. 

Liquid fuel would fall through the grate. It cannot be burned 
on a flat surface, because, being liquid, it tends to flow together 
and presents only an upper surface to the air. The use of 
trough-shaped bars along which the liquid flows and through 
which streams of air are admitted, does not get over the diffi- 
culty of small exposure of surface. 

There is no incandescent mass through which air is flowing 
to carry off the fuel in a burned state and to maintain the mass 
incandescent. If the whole of the liquid mass in a furnace did 
become incandescent, or even approached that point, it would 



THE ECONOMIES OF LIQUID FUEL 43 

distil in the form of vapour, and, if provided with air, would burn 
away uncontrollably, probably with great evolution of smoke. 
The more easily combustible or volatile portions would dis- 
appear first and the remainder would probably be left over un- 
consumed. Thus if the fire is to be controllable, the fuel must 
be supplied as it is consumed, so that at no time is there any 
serious amount of burning fuel in the furnace, and the produc- 
tion of steam is at once regulated by a simple regulation of the 
fuel supply. This end is secured by atomizing the fuel and 
discharging it into the furnace mixed with air, so that each 
atom of fuel is in contact with air, and combustion is easily 
effected. It will be found that with all the heavy liquid fuels 
atomizing is essential. 

Vaporizing. 

With lighter oil, as the cheap lamp oils used in steam motor 
cars, the liquid is supplied through a coil of pipe heated by the 
flame itself and is converted into vapour, which burns freely 
when mixed with air. With this oil it is not found that a 
deposit of carbon takes place in the retort coil, as might be the 
case with heavier oils. The lighter oils already prepared by 
distillation at a moderate temperature can thus be burned with- 
out atomizing, but, after all, their resolution into the form of 
vapour may be taken as the most complete form of atomization, 
and atomization is really a substitute for vaporization. 

Varieties of Liquid Fuel. 

In nature liquid hydrocarbon is found both free and absorbed. 
The free liquid is obtained from bore-holes put down to the oil- 
bearing stratum. When not free it is obtained by distillation 
from bituminous shales. The latter have been more employed 
for lighting or illuminating and lubricating purposes. The 
free oil or petroleum has forced its way into consideration as a 
fuel, having been employed now for many years in Russia. 
In addition to the natural oils, there are many hydrocarbons 
formed in the arts which have a high value as fuel. Of these 
there is the tar of the gas-works, a black viscous liquid which 
separates out from the gas in the process of cooling. It is 
formed in the hydraulic main and in the pipe coolers and con- 
densers. A thinner tar is produced in the condenser of oil-gas 
plant as a product of the destructive distillation of oil in the 
Pintsch gas process. Where blast furnaces are fed with coal 
in place of coke, tar is produced in the condenser pipes of the 



44 LIQUID FUEL AND ITS APPARATUS 

residuals plant, and in modern coke ovens a tar is also produced 
from the gas driven off the coal. 

Crude petroleum contains many hydrocarbon compounds 
varying from the formula CH 4 up to Cu, H 37 , the general 
formula being C n H 2 n and C n H 2n+ 2 in an isomeric series of 
many numbers. When subject to distillation some of the 
compounds are split up, and certain compounds have been 
found to contain as much as 95 per cent, of carbon. 

American Petroleum Fuels. 

In the United States the oils principally sold for fuel pur- 
poses are the by-products of crude oil ; their gravity varies 
from 23° Baume to about 34°. 

The oils of lower gravity are known usually under the name 
of Reduced Fuel Oil, and one of gravity 23 was found to analyse 
as follows — 

Carbon 87-72 

Hydrogen 11-45 

Weight per gallon 7-62 pounds 

Weight per imperial gallon 9-14 „ 

B.Th.U. per pound 19,800 

Calories, per kilo 11,000 

The oils of higher gravity are known as Distillate Fuel Oil, 
and one at the extreme end of the scale, or 34 Baume, analysed 
as follows — 

Carbon 86-19 

Hydrogen 12-51 

Weight per gallon (American) .... 7-11 pounds 

Weight per imperial gallon 8-53 „ 

B.Th.U. per pound 20,250 

Calories per kilo 11,250 

Oil being sold by the gallon an oil of 23 gravity contains 
151,066 B.Th.U., and one of gravity 34 contains 143,988 
B.Th.U. per U.S. gallon. (8J lb. of water). 

The heavier oil possesses the greater calorific capacity per 
gallon. It would be better practice to sell oil by weight or to 
state calorific capacities per gallon. For marine work the best 
oil contains the greatest heat-producing capacity per unit of 
volume, for this implies so much more efficiency of bunker 
capacity. 

Approximately the two extreme oils named contain per 
imperial gallon (of 10 lb. water) — 

Gravity 23°B = 181,340 B.Th.U. 
34°B = 172,870 B.Th.U. 



THE ECONOMIES OF LIQUID FUEL 45 

An average oil measures about one million B.Th.U. per cubic 
foot, or 35,000,000 units per 35 cubic feet of space. A ton of 
coal which occupies about 35 cubic feet contains about 33,000,000 
units of heat. In heat capacity, oil has the advantage over 
coal, apart from the fact that oil can be stored in small ballast 
tanks, and the coal bunker capacity of a ship can then be used 
for paying cargo. 

Texas and California Oils. 

These oils are used as they are found, that is to say, princi- 
pally in crude form. 

Determinations have been made of the calorific effect of these, 
and two are subjoined — 





B.Th.U. 


Calories. 


Lucas Well- Jefferson Co 

Higgins Oil & Fuel Co. — Jefferson Co. . . 


19,574 
19,785 


10,874 
10,992 



Texas oil is high in sulphur, containing this to the extent of 
2 per cent. It is said that no injurious effects are produced upon 
fire-boxes or boiler-plates generally, and it appears rational 
that this should be so. The furnace products never pass away 
except at a temperature above that of saturated steam, and 
it appears unlikely that the dry hot furnace gases should con- 
dense to moisture on the boiler-plates, especially of highly 
heated high pressure boilers. Care is of course always neces- 
sary that furnace gases shall not make contact with any surface 
water cooled below 100° F. = 38°C. Otherwise corrosion may 
occur. Dry sulphur oxides, however, seem to be innocuous. 

The Tables I, II, III, and IV are given by Sir Boverton 
Redwood, whose works may be consulted in all that relates to 
the chemistry of petroleum, which is too wide a subject fully to 
be dealt with here. 

Six thousand heat units are, states Dr. Engler, rendered 
latent in liquefying carbon, but this appears doubtful, for the 
conversion of solid carbon into gaseous carbon is not proved 
to render latent more than 5,817 B.Th.U. per pound, though 
Berthelot states that there may be a further amount, which he 
denotes as e. It is improbable that the liquid form of carbon 
will absorb so much as 6,000 units. As regards water, the 
latent heat of liquid is only about one-seventh the latent heat 
of vaporization. It is probable that a considerable difference 
exists also in the case of carbon. Against this is to be placed 



46 LIQUID FUEL AND ITS APPARATUS 

the fact that carbon has no intermediate state between solid 
and gaseous, but passes directly from one to the other when 
burned. It can only be said to be liquid when combined with 
other elements. 

Russian Petroleum. 

Russian oils are the inverse of the American oils, for while 
the latter contain about 25 per cent, of residuum, the former 
may contain 75 per cent. Astatki or residuum varies from 
35 to 60 per cent, of the crude oil, and is really the chief product 
of the Russian oils. 

The specific gravity of crude petroleum varies from 0-771 to 
1-020, and the following general values are given by Sir Boverton 
Redwood. 

Sp. Gr. 

Crude petroleum (Redwood) .... 0-771 to 1-020 

American (Hofer) 0-785 to 0-936 

Wyoming 0-945 

Galician 0-799 to 0-902 

Baku 0-854 to 0-899 

Canada 0-859 to 0-877 

The percentage of residue in various oils is given as follows— 

Pennsylvania 5 to 10% 

Galician 30 to 40% 

Roumanian 25 to 35% 

Alsace 35 to 60% 

Baku 36 to 60% 

The composition of oils is thus very varied. 

Creosote Oils. 

Properly speaking, creosote is that distillate from coal tar 
which is intermediate between crude naphtha and pitch. 

It is sometimes called dead oil and heavy oil, because its 
specific gravity is greater than unity. 

In a wider sense creosote oil is understood to include the 
heavier oils from bituminous shales as well as the liquid de- 
posited from coke oven and blast furnace gases. These various 
oils are all combustible, and though by no means properly 
called creosote, the distinction is not of importance as regards 
their value as fuel. 

True creosote is probably too valuable as an antiseptic in 
wood preservation to allow of its very extensive use as fuel. 

Coal tar creosote consists of that part of the tar which distils 
between 200°C. and 300°C, and includes various naphthalene 
bodies, etc. In colour it is yellow green and fluorescent. Its 
specific gravity is 1-10 to 1*024, according to quality, the 



THE ECONOMIES OF LIQUID FUEL 



47 



London made oils being heavier than provincial oils, simply 
because London is supplied largely with Newcastle coal, while 
country oils are from Midland coals of different quality. 

As regards the constituents of creosote, the chief are naphtha- 
lene, carbolic acid and cresylic acid, and the composition of 
these bodies is as follows — 

Creosote. 





Formula. 


Percentage composition. 


Constituent. 


Carbon. 


Hydrogen. 


Sp. Gr. 


Melting 
Point. 


Naphthalene 
Carbolic acid 
Cresylic acid 


C 6 H e O 
C 7 H 8 


93-75 
76-5 

77-78 


6-25 

6-3 

7-4 


0-978 
1-056 
1-04 


79°C. 
42°C. 
33°C. 



The foregoing is a very brief summary of the properties oi 
creosote oils. Full information is to be found as regards the 
chemistry of the coal tar compounds, in vol. ii. of Allen's 
Commercial Organic Analysis. The above will serve to show 
that these tar products are largely combustible, and may be 
burned in the same way and with the same apparatus as used 
for petroleum. 

The fuel oil of the Anglo-American Co. is crude oil deprived 
of its more volatile constituents. Its specific gravity is 0*893 
to 0-910 at 60°F., and the closed test flash point is 220° to 
250°C.,and the calorific value 19,000 to 19,800 B.Th.U. per lb. 

Blast furnace oil has a specific gravity of 0-988 ; shale oil 
creosote is similar. Coal tar from gas works has a specific 
gravity of 1-10 to 1-20, and is very complex in composition. 
London tar contains from 2-5 to 8 per cent, of ammoniacal 
liquor, 0-5 to 3*4 per cent, of light oils, 17 to 23 per cent, of 
creosote and carbolic oils, 13 to 17 per cent, of anthracene oils, 
and 58 to 62 per cent, of pitch. 

The distillates from coal, bituminous shale and wood all 
contain more or less oxygenated bodies. Coal and shale dis- 
tillates contain some nitrogenized bodies. Petroleum, on the 
other hand, contains only hydrocarbons. 

Shale tar has a specific gravity of 0-865 to 0*894 according to 
the method of retorting practised. It consists of a complex 
mixture of hydrocarbons of the paraffin order C n H 2n+2 ; of 
the olefin order C n H 2n , and of hydrocarbons C n II 2n _ 2 with 
some oxygenated bodies. 

About thirty gallons of oil can be distilled from each ton of 
shale. 



CHAPTER III 

THE CHEMISTRY OF TEXAS PETROLEUM 

IN Bulletin No. 4 the Chemical Laboratory of the University 
of Texas, Dr. E. Everhart gave the results of an examin- 
ation of the Nacogdoches oil, the analysis having been made 
by Mr. P. H. Fitzhugh. The report says — 

" The oil has a brownish-red colour. The odour is peculiar, 
but not so offensive as the crude petroleum of Pennsylvania. 
At ordinary temperature the oil is mobile, but not so much so 
as ordinary petroleum. Submitted to extreme cold, the oil 
still retains its liquidity, but becomes less mobile. The tempera- 
ture of the oil was reduced to less than zero (Fahrenheit) 
without it losing its flowing qualities. 

" At no temperature attainable in the laboratory by artificial 
means could any solid paraffin be separated. The oil does not 
gum on exposure to the air. It is not adapted to the produc- 
tion of illuminating oil ; its value consists in its use as a 
lubricant. 

" About four pounds of oil was subjected to distillation over 
the naked name in a retort connected with proper condensers. 
The temperature was carried up to 680°F. At intervals of 
45° each distillate was removed and its weight determined. 
The results of the distillation were as follows — 

Analysis of Nacogioches Oil. 

Per cent, by weight. 

Below 300°F 0-04 

300° to 345°F . . . . 0-37 

345° to 390°F 138 

435° to 480°F. . 3-14 

480° to 525°F 6-25 

525° to 615°F 7-07 

615° to 680°F 5-63 

Remaining in the retort 74-03 

" The above figures show that the crude petroleum is practi- 

48 



THE CHEMISTRY OF TEXAS PETROLEUM 49 

cally free from naphtha, which distils off below 250°F. Four 
pounds of this oil carried to a temperature 50° higher yielded 
only a few drops of a light oil, amounting to 0-04 per cent, of 
the total amount taken. In the Pennsylvania crude petroleum 
the illuminating oil comes off between 250° and 500°F., and, 
on an average, amounts to about 55 per cent. The Nacog- 
doches petroleum between the same degrees of temperature 
yields only a little over 7 per cent. Three-fourths of the oil 
does not boil until a temperature above the boiling point of 
mercury is reached. Above 400°F. and even lower the dis- 
tillate is not pure white, but is somewhat coloured. This 
colour deepens on exposure to the atmosphere. The distillate 
exhibits fluorescence. 

" The density at 62-6°F. is 0-9179. That of Pennsylvania oil 
is usually about 0*794 to 0-840. The co-efficient of expansion 
is 0-02568." 



Properties of Petroleum. 

W. B. Phillips, Ph.D., of the University of Texas, says — 

" In weight (specific gravity), taking water as 1,000, it varies 
from 650, as in certain oils from Koudako, Russia, to 1,020, 
as in the oil from the island of Zante. The range is, however, 
for the most part, between 770 and 940. A gallon of crude 
petroleum will vary from 6-41 pounds to 7-83 pounds for the 
United States gallon, and from 7*20 to 9 40 pounds for the 
Imperial gallon. Exclusive of the barrel, the 40 gallons, or- 
dinarily spoken of as a barrel of oil, will weigh from 269-22 
pounds to 328 '86 pounds. 

"With regard to its flow, crude petroleum may be quite mobile, 
as in the light-coloured varieties, or quite viscid, as in the black 
varieties. The temperature at which it becomes solid ranges 
from 82 °F., as in oil from Burma, to several degrees below zero. 
The flash-point (the lowest temperature at which inflammable 
vapours are given off) varies from below zero, in certain oils 
from Italy, Sumatra, etc., to 370°F. in oils from the Gold Coast, 
Africa. The ordinary range of the flash-point, however, does 
not show such extreme limits." 

For oils whose flash-point lies below 60°F. the specific 
gravity ranges from 771 to 899, the average being 838. On 
the other hand, the oils whose flash-points are above the boiling- 
point of water have a range of specific gravity from 921 to 1,000, 
the average being 959. It is remarkable that a Roumanian oil 
with a flash-point of 24°F. should have had a specific gravity 

D 



50 LIQUID FUEL AND ITS APPARATUS 

of 899. As a general rule low specific gravity accompanies a low 
flash-point. In none of the examples examined, whose flash 
point was above the b oiling-point of water, did the specific gravity 
fall below 921, the average being 959. There is a close con- 
nection between specific gravity and flash-point, for the presence 
of lighter oils, which are given off at a low temperature and are 
more inflammable, tends to reduce the weight of the oil as 
compared with water. This is not always so. 

The boiling-point of crude petroleum varies from 180°F. 
with certain Pennsylvania oils, to 338°F. with oil from Hanover, 
Germany. The point at which oils become solid varies from 
82°F. with oil from Burma, to below zero with oil from Italy 
and Sumatra. 

The content of carbon varies from 79-5 per cent, to 88*7 
per cent. ; of hydrogen from 9*6 per cent, to 14-8 per cent. ; of 
sulphur from 0*07 per cent, to above 2*00 per cent., and in rare 
cases even above 3*00 per cent. ; of nitrogen from 0-008 per cent, 
to 1*10 per cent. 

Hydrocarbons of the olefin series occur in nearly all kinds of 
petroleum, but are specially characteristic of Russian petroleum 
from Baku. 

Mabery has shown that the distillate from Beaumont oil 
coming over between 266° and 275°F., gave hydrocarbons of the 
acetylene and benzine series, and the same was true of the 
distillate coming over between 311° and 320°F. He also found 
this oil to contain 2-16 per cent, of sulphur and more than 
1-00 per cent, of nitrogen. 

There is no hard and fast line of demarcation. The chemical 
properties shade into each other, and only a general statement 
can be made that the oils from Pennsylvania fall into the 
paraffin series and the Russian into the olefin series, while 
the Beaumont oil is a third class distinguished by the presence 
of members of the acetylene and benzine groups. 

Bituminous coal contains much less carbon and hydrogen 
and much more oxygen than petroleum. Anthracite coal 
has about the same amount of carbon as petroleum, but much 
less hydrogen and oxygen. 



THE CHEMISTRY OF TEXAS PETROLEUM 51 



Mr. E. H. Earnshaw made an analysis of Corsicana oil, 

as follows: — 



Analysis of Petroleum from Corsicana 


, Texas. 




i 


Per cent. 


Sp. Gr. at 

60°F. 


Fractions. 


±emperature, 
F. 


By Vol. 


By 

Weight. 


Colourless 

A 

B 

C 

D 

E 

F 

G 

Very faint yellow 

H 

I 

Yellow, J 

Deep reddish yellow, K . 
Deep red (solid), L, over . 
Dark red-brown (solid), M, over 
Residue 


130°-200° 

200°-250° 
250°-300° 
300°-350° 
350°-400° 
400°-450° 
450°-500° 

500°-550° 
550°-600° 
600°-650° 
650°-665° 
650° 
650° 


2-80 
5-10 
7-60 
8-20 
9-40 
7-40 
8-30 

6-45 
7-75 
14-95 
17-25 
1-30 
1-40 
2-63 


2-24 
4-31 

6-69 
7-44 

8-75 
7-07 
8-09 

6-43 
7-85 
15-43 
1807 
1-41 
1-63 


0-6653 
0-7017 
0-7302 

0-7527 
0-7718 
0-7920 
0-8088 

0-8260 
0-8404 

0-8555 
0-8687 
0-8972 
0-9669 


Total 




97-90 


98-04 





Mr. Thiele's remarks on the oil were as follows — 

" The oil is very dark brown and opaque, but thin and fluid 
at 60°F. The specific gravity at 60°F. is 08292. The oil is 
closely related to the oil from Washington district, Perm., but 
contains asphaltum or bodies similar to it. 

" Nacogdoches oil is heavy, specific gravity 0*915. The 
colour is black, and there is much sulphuretted hydrogen. 

" Oil from Saratoga, Hardin county, is heavier, the specific 
gravity being 0995. It is black and rich in asphaltum. 

" Oil from Sour Lake, Hardin county, has a specific gravity 
of 0-963, and analyses as follows — 

Analysis of Petroleum from Sour Lake, Hardin County, Texas. 



Fractions. 


Temperature 
F. 


Per cent, 
by Vol. 


Specific 
Gravity. 


Colour, etc. 


1 

2 
3 
4 
5 
6 
< 7 
Residue . 


212°-266° 
266°-320° 
320°-392° 
392°-572° 

572°-641° 


0-07 

0-03 

1-59 

19-49 

5-15 
71-11 


0-684 
0-840 

0-782 
0-978 


Yellow 
Yellow 
Yellow 
Yellow ; blue fluorescence 

Dark yellow 
Black 


Total . 




97-44 







52 



LIQUID FUEL AND ITS APPARATUS 



In the Journal of the Society of Chemical Industry, vol. xix., 
No. 2, February 28, 1900, Mr. Clifford Richardson has the 
following — 



Corsicana Oil. 



Specific gravity, 68°F. 

Baume 

Flash 

Volatile, 212°F. . . 
Volatile 324°F., 7 hours 
Volatile 339°F., 5 hours 



0-8457 
35-6 (about) 
Ordinary temperature. 
10-8 per cent, (naphtha). 
35-7 
11-2 



Total 57-7 



Residue, after heating to 323°F., flows readily at 68°F., 
appears to contain paraffin. After heating to 399°F. residue 
has a quick flow at 77°F. 



Sour Lake Oil. 



Specific gravity, 68°F. 

Baume 

Flash 

Volatile, 212°F. . . 
Volatile, 324°F., 7 hours 
Volatile, 399°F., 5 hours 



0-9458 
18-0 
244°F. 

22-8 (water with trace of oil) 
12-6 
14-4 



Total 49- 



After 



Residue after heating to 324°F. flows readily at 70°F. 
heating to 399°F., residue flows readily at 77°F. 

The specific gravity of Corsicana petroleum is a little greater 
than that from near Dudley, Noble county, Ohio, 8457 to 
0-8333. 

Distilled under ordinary pressure, without particular pre- 
cautions to prevent cracking, Mr. Thiele found — 

Sp. Gr. 

Naphtha, 10-8 per cent 0-710 

Kerosene, 54-5 per cent 0-796 

Residue, 34-7 per cent 0-905 

Twenty grams of the oil, heated for seven hours in an air 
bath at various temperatures in a crystallizing dish 2 J inches 
in diameter by 1| inches high, left a residue of 43*3 per cent., 
which flowed readily at 77°F. The residuum resembles that 
from Pennsylvania and Ohio petroleum, and apparently con- 
tains paraffin scale. It is to a certain extent asphaltic. The 
crude, when distilled under a pressure of 1 inch of mercury, 
volatilized 51-2 per cent, at a temperature of 356°F., but began 
to " crack." Ohio oil did not begin to " crack " until 455°F. 



THE CHEMISTRY OF TEXAS PETROLEUM 53 

at atmospheric pressure ; but the Sour Lake oil broke up at the 
same point as did the Corsicana. It is, therefore, a less stable 
oil than eastern petroleums. 

The Sour Lake oil is a very heavy crude petroleum, 18b, 
and corresponds in many respects with some of the heavier 
California oils of Summerland and Los Angeles in appearance 
and properties. It flashes at a low point for such a heavy 
oil, 244°E. 



Properties of various Petroleums. 

The following table is taken from Sadtler's Industrial Organic 

Chemistry — 



Crude Oil from 


Sp. Gr. at 


Began 
to boil 


Under 
302°F. 


302° to 572° 


Over 581° 




63°F. 


at °F. 


per cent. 


per cent. 


per cent. 


Texas-Corsicana 


0-821 


176 


34-6 


40-0 


15-8 


Pennsylvania 


0-818 


180 


21-0 


38-0 


40-7 


Galicia . 


0-824 


194 


26-5 


47-0 


26-5 


Baku 


0-859 


196 


23-0 


38-0 


39-0 


Alsace . 


0-907 


275 


33-0 


50-0 


47-0 


Hanover . 


0-899 


238 




32-0 


68-0 



Dr. W. H. Harper, Professor of Chemistry in the University 
of Texas, gives an analysis of a sample of Corsicana oil — 

Colour, very dark brown, almost black ; opaque except in 
thin layers ; greenish fluorescence. 

Viscosity, not determined, but the oil very mobile at 32° F. 

Sediment, none. 

Water, none. 

Flash-point, 73°F. 

Specific gravity at 635°F., 0-8586, equivalent to 33° Baume. 

Calorific Capacity of Petroleum. 

The B.Th.U. in petroleum vary from 17,000 to 20,000, one 
experiment giving 20,110. The value taken in Texas is 
18,500 B.Th.U., or 10,277 calories. The scientific investiga- 
tion of the coals, etc., used there, with respect to their heat 
units, has not progressed very far ; but it is not thought that, 
on the average, the B.Th.U. in the coals will be above 12,600, 
if indeed above 10,800, and are taken, for the present, at 11,700. 
For the lignites a lower value must be taken, and for the present 
this will be 9,900. 

Some of the Alabama coals have 13,500 B.Th.U. ; good 



54 LIQUID FUEL AND ITS APPARATUS 

McAlester coal (Indian Territory) maybe taken at the same ; 
New Mexico coal at 12,000 ; and lignite at 9,900. On this basis 
one barrel of crude petroleum, weighing 320 lb. net. would be 
equivalent to 438 lb. of Alabama coal, and the same amount 
of McAlester coal, 493 lb. of New Mexico coal, and 598 lb. of 
lignite. A ton, 2,000 lb., of Alabama coal would then be 
equivalent to 4-56 barrels of petroleum ; a ton of McAlester 
coal to 4* 5 6 barrels ; a ton of New Mexico coal to 4-06 barrels ; 
and a ton of lignite to 3*34 barrels. In other words, from 
3J to 4J barrels contain as many heat units as a ton of the best 
coals and lignites of American Southern States. 

Experiments made in California with a view to testing the 
relative value of the California oil and the coal with which it 
comes into competition, showed that a ton of Nanaimo coal, 
giving 12,031 B.Th.U., was equivalent to a minimum oil 
consumption of 3-45 barrels and a maximum consumption of 
3* 87 barrels. Experiments on Texas petroleum showed it to 
have 19,160 heat units, and this would be equivalent to 4-29 
barrels per ton of Indian Territory coal. In Russia the usual 
equivalent is 3*12 barrels per ton of coal. 

There is considerable variation in the quality of coal, and 
these differences are often observable in coal from the mine, 
due, perhaps, to carelessness in mining and handling, and to the 
absence of rigid inspection. In countries where coal is sold 
on the basis of heat units these discrepancies are less. Varia- 
tions in the quality of oil from the same well are by no means 
so marked as in the case of coal from the same mine. The 
practice of piping different oil into the same storage tanks 
tends to advance uniformity. 

The value of oil as compared with coal varies with the nature 
of the work to be done. It has been observed that in puddling 
and steel-heating furnaces 2 J barrels of Los Angeles oil were 
equivalent to 2,000 pounds of Wellington coal from British 
Columbia, while for steaming purposes it took three barrels of 
the oil for one ton of the coal. In some establishments in Los 
Angeles the proportion rose to 3-62 barrels per ton ; in others, 
to 3*10. On the Southern Pacific Railway it has been found 
that four barrels of California oil were equivalent to one ton 
of Nanaimo, British Columbia, coal. The lowest consumption of 
oil per ton of coal that has been found is 2J barrels, while the 
highest is 4 barrels. In a general way, from 3| to 4 barrels of oil 
should be equivalent to a ton (2,000 pounds) of good soft coal. 
The lower figures may be reduced under good practice and 
management and the best appliances to 3 J barrels ; while under 
bad management, etc., the higher figure may reach 4J barrels. 



THE CHEMISTRY OF TEXAS PETROLEUM 55 

Advantages of Liquid Fuels. 
The advantages to be derived from the use of liquid fuel are — 

1. Diminished loss of heat up the funnel (or chimney), owing 
to the clean condition in which the boiler tubes can be kept, 
and to the smaller amount of air which has to pass through the 
combustion-chamber for a given fuel consumption. 

2. A more equal distribution of heat in the combustion- 
chamber, as the doors do not have to be opened, and a higher 
efficiency is obtained ; unequal strains on the boiler tubes, etc., 
due to undue heating, are also avoided. 

3. No danger of having dirty fires on a hard run. 

4. A reduction in the cost of handling fuel. 

5. No firing tools or grate-bars are necessary ; consequently 
the furnace lining, brickwork, etc., last longer. 

6. Absence of dust, ashes and clinkers. 

7. Petroleum does not deteriorate on storing, while coal does, 
especially soft coal. This opinion is not universal, however. 

8. Ease with which the fire can be regulated from a low to a 
most intense heat in a short time. 

9. Lessening of the amount of manual labour in stoking. 

10. Great increase of steaming capacity, the difference being 
as much as 35 per cent, in favour of oil. 

11. The absence of sulphur or other impurities, and longer 
life to plates, etc. ; but considering the fact that the amount 
of sulphur in some of the oils now being used as fuel is in excess 
of the sulphur in ordinary coals, this point is not well taken. 
Sulphur is objectionable in any fuel, whether coal or oil, and 
of the two may be more objectionable in oil than in coal, for a 
portion of the sulphur in coal remains in the ashes, and is not 
consumed. 

If crude petroleum, or the residue from refining plants, is to 
come into use on a large scale as fuel, there are some consider- 
ations that must be weighed, in addition to its fuel value, viz., 
its initial price, f.o.b. tanks or wells, transportation charges, 
and the like. 

Profiting by the experiences in California and elsewhere in the 
use of oil for fuel, many industrial establishments in Texas 
changed from coal to oil. Among the first was the American 
Brewery, Houston, with two 200 h.p. and two 350 h.p. 
boilers. The oil was the residue from the refining plant at 
Corsicana, and it was estimated that 75 barrels a day would 
be required, as the coal consumption was about 25 tons a day. 
After running for a while, it was stated that the steaming 
capacity of the two 200 h.p. boilers using oil was equivalent 



56 LIQUID FUEL AND ITS APPARATUS 

to that of the two 350 h.p. boilers using coal, and the saving 
of oil was about 33 per cent. The Star Flour Mills, Galveston, 
installed oil burners in April, 1901, using about 35 barrels a 
day for a 350 h.p. engine. 

The first locomotive equipped for burning oil was delivered 
to the Gulf, Beaumont and Kansas City Railway, June 20, 
1901, and belonged to the Gulf, Colorado and Santa Fe Railway. 
Up to the time of its reaching Beaumont it had travelled 450 
miles, and consumed 42 barrels of oil, the tank having this 
capacity. The Southern Pacific Railway burns oil west of El 
Paso. 

Tests of Texas Oil Efficiency. 

A report by Professor Denton states that the number of 
barrels of oil equivalent to 2,240 pounds of coal was 4-23 for 
one h.p. per about twenty square feet of heating surface, and 
4-12 for one h.p. per 10 square feet of heating surface ; and it 
appears that the average consumption of oil per ton of coal is 
four barrels, and that under some conditions this falls to 3-50 
barrels. There may be consumers who use even less than this, 
but it is not thought that they represent the average practice. 

Beaumont oil was used to operate a boiler at the plant of the 
West Side Hygeia Ice Company, West 19th Street, N.Y. City. 
There were three return tubular boilers, each 6 feet in diameter 
and 18 feet long, containing about 1,900 square feet of heating 
surface, two being used at a time to provide about 180 boiler 
h.p. from buckwheat coal, with natural draught under a very 
steady load throughout each 24 hours. One of these boilers 
was fitted for the tests with the Williams Oil Burner. 

Effect of the Oil on the Boiler and Furnace. 

After the steam-raising test, the boiler was operated 24 hours 
with oil, to use up all that remain of the 117 barrels provided 
for the evaporative test. It was then cooled, and the oil- burning 
apparatus removed to prepare the furnace for coal tests. The 
boiler and furnace were then examined. No trace was found 
of any action of the oil on the boiler. There was no oily matter 
on the internal brickwork, nor any discolouration of the latter, 
and there was less than -^ of an inch of soot in the tubes, 
which had been swept clear of ashes at the beginning of the 
use of the oil. 

The tests with oil were made at from 112 h.p. to 220 h.p. 
The boiler was 6 feet in diameter and 18 feet long of the hori- 
zontal return tube type. It had 100 tubes 2| inches in diameter, 



THE CHEMISTRY OF TEXAS PETROLEUM 57 

and a grate surface of 45-5 square feet, i.e. 6 feet 6 inches by 
7 feet inches. Height of chimney, 70 feet high by 42 inches 
square. The resume of the tests is as follows — 

Resume of Tests with Beaumont Crude Oil. 



Duration, hours .... 


3-5 


8 


11 


13 


11 


Horse power 


146-9 


122-7 


189-7 


1380 


2201 


Steam pressure (gauge), lb. . 
Feed temperature, degs. F. 
Chimney temperature, degs. 
F 


87 
69° 

374° 


86 
90° 

360° 


86 

70° 

398° 


86 
90° 

370° 


86 

74° 

425° 


Quality of steam. 
Oil per hour per sq. ft. of 
heating surface, lb. 


dry 
0-181 


dry 
0-135 


dry 
0-226 


dry 
0-063 


dry 

0-263 


Dry steam per hour, from 
and at 212° per sq. ft. of 
heating surface, lb. 


2-73 


2-09 


3-52 


2-56 


4-08 


Heating surface perh.p., sq. 
ft 


12-6 


16-5 


9-8 


13-5 


8-45 


Total dry steam per lb. of 
fuel as fired from and at 












212°F., lb 


15-29 


15-53 


15-55 


15-71 


15-49 


Per cent, of steam used by 












burner 


3-6% 


3-1% 


4-8% 


3-5% 


4-8% 


Net lb. of dry steam per lb. 
of fuel fired from and at 












212°F 


14-74 


15 05 


14-80 


15-16 


14-75 



Other figures are as follows — 

Dimensions and Proportions. 

Grate surface, sq. ft 45-5 

Water heating surface 1,860 

Position of damper Wide open 

Area of opening of ash pits, sq. ft 1-8 

Average Pressures. 

Steam pressure, by gauge, lb 86-5 

Draught pressure, inches of water 0-37 

Average Temperatures, Fahr. 

Fire room * 53-1 

Feed water entering boiler . 74 -C 

Chimney gases 42-£ 

Fuel. 

Weight of fuel as fired, lb 5,39c 

Steam. 
Quality of steam dry 



58 LIQUID FUEL AND ITS APPARATUS 

Water. 

Total weight of water fed to boiler, lb 70,798 

Factor of evaporation 1-180 

Equivalent water evaporated into dry steam from and 

at 212°F 83,542 

Economic Results. 

Feed water per lb. of fuel as fired, lb 13-13 

Equivalent evaporation from and at 212°F. per lb. of 

fuel as fired, lb 15-49 

Equivalent evaporation from and at 212°F. per lb. of 

combustible, lb 15-49 

Efficiency. 

Efficiency of boiler and furnace, or heat per lb. of fuel as 

fired, divided by calorific value per lb. of fuel . 78-5% 

Efficiency of boiler, or heat absorbed by boiler, per lb. of 
combustible, divided by calorific value per lb. of 
combustible 78-5% 

Hourly Quantities. 

Fuel as fired per hour, lb 490-3 

Fuel as fired per hour per sq. foot of grate, lb. . . 10-78 
Combustible per hour per sq. foot of heating surface, lb. 0-263 

Horse Power. 

Horse power at 34-5 lb. from and at 212° . . . . 220-1 
Heating surface per horse power, sq. feet .... 8-45 

Compositions of Fuel. 

Per cent. 

Carbon 85-03 

Hydrogen 12-30 

Oxygen and nitrogen 0-92 • 

Sulphur 1-75 

Heat Balance. 

B.Th.U. 

Utilized in production of steam 14,963 

Due to combustion of hydrogen . 1,245 

Wasted in superheating water products . . . . 113 

Wasted in dry chimney gases 1-837 

Radiation and imperfect combustion 902 

Heat per lb. of fuel as fired, by calorimeter . . . 19,060 

Heat per lb. of combustible, by calorimeter . . . 19,060 

The weight of oil per gallon was 7*66 pounds, or 322 pounds 
per barrel of 42 American gallons of 231 cubic inches. The net 
evaporation, per pound of oil. from and at 212°F., was 15*1 
pounds ; per pound of Pennsylvania bituminous coal, in the 
best boilers at 10 square feet of heating surface per h.p. is 
9-5 pounds ; of the semi-bituminous coals, such as Pocahontas, 



THE CHEMISTRY OF TEXAS PETROLEUM 59 

New River, Cumberland and Clearfield, it is 10*0 pounds, which 
may be increased to 10-5 and 11 pounds by mechanical stokers, 
or smoke-preventing devices. 

Professor Denton calculates the comparative costs of oil and 
coal as follows — 



Price of coal per ton 
of 2,240 lb. 

$1.00=4/- 
1.50 = 6/- 

2.00 = 8/- 
2.50 = 10/- 
3.00 = 12/- 
3.50 = 14/- 
4.00 = 16/- 
4.50 = 18/- 



Equiv. price of oil per barrel, 
of 42 gallons. 
$0.29 = 1/21 
0.43 = 1/9 i 
0.56=2-4 
0.71=2/111 
0.85 = 3/61 
0.99=4/11 
1.13=4/81 
1.28=5/4" 



These figures apply to bituminous coals mined west of Ohio. 
In comparison with small sizes of anthracite, Pittsburg bitu- 
minous and Maryland and West Virginia semi-bituminous coals, 
and most or all British coals, oil must be sold at a less price, 
inasmuch as these fuels are of a better quality than Western 
and South- Western coals. 

Evaporative Duty. 

Professor Denton's results show that the net evaporation 
ranged from 1474 to 15-16 pounds of water per pound of oil, 
the h.p. varying from 112 to 220 and the burner steam con- 
sumption from 31 to 48 per cent, of the boiler output. The 
boiler utilized about 78 per cent, of the heat of the fuel, which 
may be considered the best average boiler practice. It is also 
to be observed that the results in actual practice showed that 
98 per cent, of the total heat of combustion of the oil, as deter- 
mined by the calorimeter, was accounted for by the steam pro- 
duction, the chimney gases and a reasonable allowance for 
radiation. Professor Denton thinks that for a higher horse- 
power a net evaporation of 148 pounds of water is the best 
economy that can be expected from the use of oil as fuel with 
steam jet burners. This may be contrasted with 1P79 pounds 
yielded by excellent No. 1 buckwheat coal. 

Considering the objections that have been raised against the 
use of crude oil, on account of its content of sulphur, it may be 
said that many excellent steam coals carry from 1*5 to 2 per cent 
of sulphur, and that the average fife of a boiler does not seem 
to be impaired by their use. The amount of sulphur in the oil 
used by Professor Denton was 163 per cent. Allowing that a 
coal contains 1*7 per cent., an oil would have to contain 26 per 
cent, in order to put as much sulphur into the products of com- 






60 



LIQUID FUEL AND ITS APPARATUS 



bustion as the coal, equal horse-powers being assumed. It has 
been ascertained that the use of coal carrying more than 3 
per cent, of sulphur does not cause any greater depreciation of 
fire-boxes, etc., than a coal of 1*7 per cent, of sulphur, and the 
sulphur equivalent in oil corresponding to 3 per cent, in coal is 
above 6 per cent. The objections to the use of crude oil, based 
on its sulphur content, do not appear to be well founded, in so 
far, at least, as concerns the integrity of fire-boxes, etc. Pro- 
bably sulphur products are only seriously harmful when cooled 
to moisture point. 

The inflammability of crude oil has been the subject of critical 
investigation. There was no inflammable vapour given off 
below 142°F. in Professor Denton's experiments ; and he does 
not think that a pool of oil in a boiler room would become 
ignited from a lighted match or from the dropping of a live coal 
into it. It is also stated that a surplus of oil at the burner gave 
rise merely to a thick smoke ; there was no explosion or excess 
of pressure. 

One more point of a most important nature was brought out 
by the test. It was not a new point, for other tests have estab- 
lished the fact, and it is well known to those who study the 
economies of fuel consumption. It is the comparative efficiency 
of oil and coal referred to the heat balance. 





Oil. 


Coal. 




B.Th.TL 


Per cent. 


B.Th.U. 


Par cent. 


Utilized in production of steam. 

Evaporation of moisture in fuel and 
due to combustion of hydrogen . 

Wasted in superheating water pro- 
ducts 

Wasted in dry chimney gases . 

Wasted in unconsumed carbon in ash 

Radiation and imperfect combustion 

Heat per pound of f uel as fired, by 
calorimeter 

Heat per pound of combustible, by 
calorimeter 


14,963 

1,245 

113 
1,837 

902 

19,060 

19,060 


78-5 

6-5 

0-6 
9-7 

4-7 

1000 


8,636 

277 

23 
1,981 

768 
415 

12,100 

14,680 


71-4 

2-3 

0-2 

16-4 

6-3 

3-4 

100-0 



This table shows that more heat units were given off by the 
oil than corresponded with the total number of heat units 
in the coal, and that the percentage of heat units used was 
78-5 of those in the oil, as against 71*4 of those in the coal ; 
in other words the oil was more efficient than coal. The saving 
of the heat ordinarily wasted in dry chimney gases is especially 
noteworthy, for the oil shows a waste of 9*7 per cent., as against 



THE CHEMISTRY OF TEXAS PETROLEUM 61 

16*4 for the coal. In comparison with coal yielding 12,100 
B.Th.U. per pound as fired, and 14,680 per pound of combustible, 
there is a decided economy in the use of crude oil under the 
conditions maintained in this test. 

That returns from consumers of oil show a difference of 
43 per cent. (i.e. from 3*5 to 5) in the number of barrels of oil 
equivalent to a ton of good soft coal, is evidence that ordinary 
experience cannot be relied on to afford, anything more than a 
rough approximation. If the ordinary steam installations 
were provided with smoke-preventing devices and mechanical 
stokers, it is very probable that the economy in the use of oil 
would not be so pronounced. 

If all the economies possible in the use of the solid fuels 
were maintained, the comparison between these and oil would 
not be so strongly in favour of the latter. When smoke- 
preventing appliances are installed alone or in connection with 
mechanical stoking more particularly, a saving of more than 
20 per cent, has been regularly obtained, with ordinary coals. 
It is to be doubted whether ordinary practice with solid fuels 
has attained its maximum economy. Establishments where 
great attention is paid to all possible economies in fuel consump- 
tion form the exceptions. 

We may allow that the heat units in oil are more easily avail- 
able for steam-raising purposes than the heat units in coal, and 
that, per unit of heating power, we get better results from oil 
than from coal. When we have once ascertained what we can 
get from the oil, we can calculate the relative advantages in 
the use of the two. It is, after all, a matter of cost, and each 
particular installation must be considered on its merits. 

Mexican Oil. 

Mexico is now a large producer of oil. Mexican Fuel Oil 
has the following characteristics : — 
Sp. gr., about 0-95 at 60° F. 
Flash point, over 150° F. (open). 

Viscosity, about 1,500 sees, at 100° (Redwood No. 1), 
Calorific Value, 18,750 B.Th.U, 
Sulphur, 3-5 per cent. 



CHAPTER IV 

THE CHEMICAL AND OTHER PROPERTIES OF PETROLEUM 

IN a work of this description a deep study of the chemistry 
of liquid fuels is not necessary. For fuller information 
on petroleum chemistry the works of Sir Boverton Redwood 
may be studied. 

Petroleum is a mixture of a series of hydrocarbons of the 
following types — 



1. 

2. 
3. 


C n H 2n+2 Methane Series. 
C n H 2n Olefin Series. 

C n H 2n _2 


4. 

5. 
6. 


>» -4 

„ _ fl Benzene Series. 

» -8 


7. 


j> -10 


8. 


>> -12 



Those named occur in the greatest quantity and most fre- 
quently. The first is a light gas in the form CH 4 , and as the 
values of n in each series grow larger, the members of the various 
series become liquid and finally solid. 

Thus of the first or Methane series the first four are gaseous, 
Methane, Ethane, Propane, and Butane. Series 1 is liquid 
when n = 5 to 25. Above n = 25, the solids begin and generally 
in all the series a higher value of n implies a higher boiling 
point, and this rises with some regularity from n = 9, by about 
20°C. = 36°F. for each additional carbon atom. Hence the ease 
with which fractional distillation can be carried on, the light oils 
(gasoline, ect.) distilling off up to 150°C, the illuminating oils 
up to 300°C, and the residuum being fuel oil, which still con- 
tains the lubricating oils. 

Dr. Paul, in discussing Aydon's paper, suggested that liquid 
fuel had an advantage over solid fuel to the extent of 6,000 
B.Th.U. per pound, which he claimed as the latent heat of 
liquefaction, but this is elsewhere shown to be nearer the latent 
heat of evaporation of carbon, while the latent heat of lique- 
faction is scarcely credited with more than 5 per cent, extra 
calorific power, and, as pointed out by Mr. C. E. L. Orde, the 



CHEMICAL PROPERTIES OF PETROLEUM 63 

Bombe calorimeter does not show anything like Dr. Paul's 
figure. It is also probable that when carbon and hydrogen of 
the liquid hydrocarbons united, they produced heat which more 
than counterbalances the effect of the latent heat of liquefaction. 
Indeed, methane gas, CH 4 , is known to produce, when burned, 
very much less heat than calculation would appear to indicate. 
Acetylene, on the contrary, produces more heat than calculable, 
being endothermic. 

Water in Oil. 

Fuel oil and water do not readily separate. They do not 
differ much in specific gravity, and oil is so viscous that the 
globules of water cannot force their way out of it. But oil is 
rendered more liquid by heat ; it expands more than water, 
and separation is better effected by heating the oil. This is 
best done locally near the surface of the oil in the bunker, so 
that the heated oil is at once drawn ofl lor use, and heat is not 
wasted in raising the temperature of the whole bunker. 

The heat value of oil is reduced 13*14 B.Th.U. for each one 
per cent, of water. 

Thus 1 pound of oil worth 18,831 B.Th.U. mixed with 10 
per cent, of water, gives a mixture the value of which per 
pound is (18,831 x 0-9)- 131-4 = 16,816-5 B.Th.U., a differ- 
ence of 1,915-5 B.Th.U., or a loss of nearly two pounds of 
evaporation from and at 212°F. Water also reduces the flame 
temperature, lengthens the flame and moves the point of highest 
temperature further along the flues, and so diminishes the values 
of the heating surface. Mr. Orde lays down the conditions 
which show perfect combustion as an opaque dazzling white 
flame for six inches from the nozzle, becoming semi-transparent 
and almost violet in colour at middle length, shading off to 
red at the end. With water mixed in, the violet colour does 
not appear (see chapter on Smoke) and the flame becomes dark 
red and smoke-fringed. He states that at a temperature of 
140°F. = 60°C. it required seven days to separate the water 
completely in a tank of oil. Hence the use of a surface float 
as in Fig. 14a. 

His figures for the calorific value of various oils, as found by 
the calorimeter, are as follows, and show a practical identity 
of value in all, as may be expected from their chemical com- 
position — 

Borneo 18,831 B.Th.U. 

Texas. 19,242 

Caucasus 18,611 „ 

Burma ..,,,,,,,, 18,864 „ 



64 LIQUID FUEL AND ITS APPARATUS 

According to Pelouze and Cahours, there are thirty different 
hydrocarbons in petroleum, principally of the type C n II 2n+2 . 
For n = 1 and n = 2 the substance is a gas. For n = 3 the 
boiling point is 0°C. = 32°F. For n = 5 the liquid is very 
volatile, the lightest isolated by the above chemists being C 5 H 12 , 
boiling at 30°C. = 77°F. The fuel oils commence at C 8 H 18 , 
and go on to C15H32, beyond which C 2 oH 42 to C 2 8H 58 are semi- 
solid. The point of ebullition rises 20°C. = 36°F. for each 
increment of carbon from C 8 H 18 , which boils at 117° ±= 242- 6°F. 
to 197°C. = 386'6°F. for C t2 H 26 ; and 257°C = 494'6°F. 
for Ci 5 H 32 . Similarly the specific gravity increases continually, 
though less regularly, than the boiling point from C 5 H 12 , for 
which it is 0-63, to Ci 5 H 32 , for which it is 0-83. The density 
of the hydrocarbon vapours relative to air are 0*5 for n = 1 
to 7*5 for n = 15, or a growth of 0*5 for each grade. 

The Russian oils do not follow the same empirical composi- 
tion as the American, but belong rather to the ethylene series 
C u II 2n and the isomers, and to the benzene series CJK 2n _ 6 , 
of which benzene C 6 H 6 , is the characteristic member. In 
" cracking " the oils during distillation even lower forms are 
found : C n II 2n _ 8 ; C n H 2n _ 10 , which occur in the residues of 
distillation. Water may exist in the proportion of 5 per cent, 
for Baku oil to 10 per cent, for Borneo, but mineral matter is 
always small, and ash scarcely exceeds 0*3 to 0*4 per cent., but 
is an undesirable constituent for an engine, causing cylinder 
scoring. 

By " cracking," the distilled liquid becomes more and more 
stable, and the final residue is a mere coke. ■ 

Petroleum distils more easily when superheated steam is 
blown through the still while below the " cracking " point. 
The effect is peculiar to steam and cannot be secured with air. 
It appears to be a sort of solution of the petroleum by the 
steam, and Mr. Bertin, of the French Marine Militaire, con- 
siders that this affords an explanation of the superior power 
of steam in atomizing liquid fuel. A study of distillation 
shows three sorts of petroleum suitable for fuel. 

(A) Natural oils which have parted with their volatile 
portions under the influence of sun and air and become 
natural mazut. 

Borneo oil which flashes at 100°C. = 212°F. is directly 
employed as fuel, and Texas oil appears to possess little 
other value than as fuel. 

(B) Distillation residues, or mazut, which result from 
boiling off all the more volatile portions. 



CHEMICAL PROPERTIES OF PETROLEUM 65 

(C) American distilled oils as per page 44. These oils 
are very homogeneous and regular, but they emit in- 
flammable vapours below the temperatures at which they 
boil. 

The Physical Properties of Petroleum. 

These have already been partly treated of under the previous 
head, but it may be added that in common with all hydro- 
carbons and fats, petroleum and other liquid fuels become more 
fluid and lose much of their viscidity when heated. Their 
fluidity increases rapidly with heat. Hence the better atomiza- 
tion possible with heated oils. Tests at Cherbourg on mazut 
at different temperatures show that flow of oil through an orifice 
of annular form half a millimetre wide was as follows in cubic 
centimetres per minute — 

Temperature . . . 6°C. 15° 35° 70° 100° 

Flow 2-5 6-5 32 188 466 

With water at 19°C, the flow was 4,300 c.cm. 

Mazut is easily heated, its specific heat being 0*42. 

Petroleum has a rapid expansion coefficient, as much as 
0-0007 per degree Centigrade. This helps it to rid itself of 
water because, by heating the oil, both its sp. gr. and its re- 
sistance are reduced, and water can the more easily gravitate 
out. 

Though petroleum has been supposed to be unaffected by 
storage, mazut changes when exposed to air even more rapidly 
than coal, according to M. Bertin, losing its fluidity and parting 
with some of its calorific power ; experiment seems to be want- 
ing in regard to such changes taking place in closed tanks and 
not exposed to air. Any loss that may have been experienced 
may perhaps be attributed to a gradual evaporation of lighter 
oils still remaining. The fighter oils do possess the highest 
calorific capacity, and their loss would therefore to some extent 
reduce the calorific capacity of the residue. 

In Russia the sp. gr. of oil for steam raising purposes at 
17-5°C. = 635°F. must not exceed 911 to 912, and oil must 
contain no water, sand or alkali. When received the tempera- 
ture must not exceed 50°C. = 122°F. and the flash point must 
be above 140° or 150°C. = 284° to 302°F. 

Certain railroads stipulate a density of 905 to 915 at 14°R. 
= 635°F. There is no viscosity clause. 

The Navigation Co. Caucase Mercure ask for a density of 
926. The Russian Navyaccepts a flash point of 100°C. =212°F. 
and a density of 950. In America the minimum flash point of 
200°F. is usual ~ 93-3°C. 



66 LIQUID FUEL AND ITS APPARATUS 

Water in Oil. 

To determine the water q the density d is found of the sample. 
After heating for some time at 103°C. = 217-5°F. the density- 
is again found =^ 2 . The quantity of water q is determined 
by this relation (1— q) d 2 + q = d. 

The coefficient of expansion per degree C. is assumed to be 
0-000735 = 0-000408 per degree F. 

Materials. 

In the utilization of fuels for steam-raising it is necessary to 
have a knowledge more or less full of the whole of the materials 
which will be employed either as fuels or structurally. Some- 
thing must also be known of the environment in which such 
substances will be employed. 

A list of substances with which the engineer will be required 
to deal therefore includes, besides the fuel itself, air, water, 
cast-iron, steel, fire-brick, etc. 

The conditions include the ordinary atmospheric tempera- 
tures and moisture, the pressure of the atmosphere, and so on. 

The units in which ideas are expressed must also be clear. 

With this object separate sections have been given to the 
subjects of Water, Air, and Heat in its various forms, to carbon 
and hydrogen, the only two practicable fuels. A few notes 
are given below concerning some of the other materials. 

Cast-iron cannot be employed in the furnace, for it is rapidly 
destroyed by the action of fire, even when not directly in the 
flame. It should not be employed in the retort in which to 
heat and to gasify even the light-burning oils. Cast-iron tubes 
have been tried for this purpose, and have been found to become 
choked by a deposit of carbon, which may probably be due 
to some affinity between the carbon in the iron and that in the 
oil. 

Cast-iron should never be employed as a material for any 
vessel exposed to internal pressure. 

Steel. 

Steel is par excellence the material for all parts of boilers. 
Like cast-iron, it will not withstand furnace temperatures 
except when backed by water, as in the case of the plates of a 
boiler. 

Steel tubes only -^ in. thick are employed by Clarkson as 
the retort coil in which paraffin is vaporized. These coils are 
in the zone of flame, and vaporize the oil on its way to the 



FIRE-CLAY AND FIRE-BRICK 67 

burner which they surround. They possess a fair durability 
owing to the heat absorbing power of the vaporizing liquid, 
and they are found to keep free of carbon deposit. 

Fire- Bricks. 

The most important material for the furnace engineer is 
fire-clay, a material which is found beneath seams of coal. 

In a properly-set boiler for coal burning the whole interior 
of the furnace and combustion chamber will be more or less 
fluxed and run partially into drops or stalactites, which hang 
from projecting edges. With liquid fuel, fire-brick is a most 
necessary material for promoting combustion. It is a bad 
conductor of heat, and has the property of resisting high 
temperatures known as refractoriness. High furnace tempera- 
tures will render even many fire-clays liquid at the surface. 

Ordinary fire-clays contain 58 to 62 per cent, of silica, 36 to 
38 per cent, of alumina, and from 1 to 3 per cent, of ferric oxide. 

A large content of silica denotes a good and refractory brick. 

Dowlais fire-brick contains 97 J per cent, of silica and less 
than 2 per cent, of alumina, the remainder being oxide of iron, 
with a trace of lime and magnesia. 

Ganister, which is so much used in steel work, contains 89 
per cent, of silica, 5| of alumina, 2J of iron oxide, and 2J per 
cent, of material which is lost in burning. 

A brick used in France is made from diatomaceous earth 
which is nearly pure silica. These French bricks are very 
porous and light, and when dry will float in water. 

The best fire-clay comes from Stourbridge and Newcastle 
in England, Glenboig in Scotland, and Dinas in Wales. 

Makers of fire-brick supply a great variety of shapes, and 
blocks can be had for seating purposes or for furnace work, 
notably for over-fire arches and combustion chambers. 

Fire-bricks are also made for threading on water tubes, so 
as to build up refractory walls upon water tubes for the purpose 
of securing the correct direction of gases and for promoting 
perfect combustion and smokelessness. It is said that car- 
borundum is very refractory indeed, and that when finely 
powdered and made into a paint with soluble glass or silicate 
of soda, and painted on bricks, it will greatly assist in their 
preservation. Or the bricks may be dipped in the solution. 
The carborundum surface is then most refractory. 

Too little attention is paid by engineers to the fire-bricks 
they use, and heavy expenses are incurred in maintaining 
furnaces, expenses quite needless if proper attention is paid 
to the selection of the bricks. 



68 LIQUID FUEL AND ITS APPARATUS 

When a furnace is to be repaired bricks are often purchased 
from the nearest wharf, where they have lain exposed to 
weather for weeks. In their water-saturated condition they 
are built into the furnace and exposed to the full heat, with the 
result that the interior of the bricks is disintegrated and the 
bricks split up at once. 

When a fire-brick is made it should be fired at a tempera- 
ture as high as that to which it will be exposed when at 
work. 

The composition of bricks has a great influence upon their 
durability in certain surroundings. A silica brick will run like 
treacle in certain surroundings, and an alumina brick will fail 
in others, but a brick of alumina is as refractory as one of silica 
— indeed, more so as regards its ability to withstand high 
temperatures. 

Having secured the right kind of brick, a sufficient supply 
ought to be kept in store to enable them to become dry before 
use. When built into place, a slow fire only must be made and 
the heat got up gradually, so as to allow the bricks to dry 
thoroughly before being highly heated. When a boiler is laid 
off from work it should be closed up completely by shutting 
the dampers and leaving the boiler and its brickwork to cool 
as slowly as possible. 

The most troublesome detail of a furnace is the arching 
over the fire of a water tube boiler. The usual form of water 
tube boiler is very smoky, and to cure this furnace must be 
covered by a brick arch, and a capacious combustion chamber 
must be employed beyond this, so that the furnace gases and 
the air admitted above the fire may become well mixed and 
burned at a high temperature. Even with the best of bricks 
these arches are apt to fail when first fired, the face of the bricks 
dropping off. 

Messrs. E. and J. Pearson, of Stourbridge, make a special 
brick for these wide flat arches, and supply a special cement 
for use in putting them together. The cement is easily fluxed 
by heat, and cements the whole surface of the arch into a solid 
face, so that pieces of the brick cannot fall out. In time the 
whole arch welds into a solid mass. 

Such an arch ought to be built of properly-shaped bricks. 
If plain rectangular bricks are used the arch pressure becomes 
concentrated upon the intrados, and tends to flake off the 
bricks and deprive the arch of its sustaining power. The 
bricks should be of taper form so that they'fit close in the arch. 
What are known as blocks are used for these arches and for 
similar purposes^ and the above fire-brick manufacturers make 



FIRE-CLAY AND FIRE-BRICK 69 

special arch blocks with a tongue and groove joint for better 
security. 

In the formation of all important fire-clay blocks that will be 
exposed to stress, as is an arch, it is of serious importance that 
the clay be properly pugged into the mould. It is bad practice 
to put a block of clay into the mould and put it under mechani- 
cal pressure so as to force it to fill the mould. When this 
pressure method is followed the plastic clay will be internally 
fractured. Shearing planes are developed which form planes 
of cleavage or fracture. The movement may be very slight, 
but lines of weakness will be developed and the homogeneous 
continuity of the mass of the clay will be destroyed. When 
burnt, the adhesion along these planes of weakness will be 
imperfect and when at work such a block will fail. 

A really good arch should last a year if built from a firm 
springing. The thrust of an arch is considerable and must all 
be taken by the side walls, which, not as a rule carrying the 
weight of the boiler, may not be very stable, and it is desirable 
to tie them down to the foundation by through vertical bolts, 
so as to form a stiff unyielding support for the arch springing. 

The subject of fire-brick is one that has not been much 
studied by engineers. Steel melters and others who deal with 
high temperatures have paid attention to the question. The 
burning of coal for steam raising purposes has, however, been 
so invariably carried out at comparatively low temperatures 
that the importance of fire-brick has not been perceived. When 
a steam engineer begins to experience trouble with his furnace 
side wall lining he casts about him for some means of meeting 
that trouble, and his efforts may take the shape of a water box. 
High temperature he regards, when it occurs, as a disagreeable 
incident, to be checked and avoided. If he understood com- 
bustion he would welcome the temperature as a means of 
securing more perfect combustion, and would endeavour to 
meet the trouble by the provision of suitable fire-brick. 

The high temperatures obtainable with oil fuel bring the 
fire-brick problem into greater prominence, and direct attention 
to this most important material. 

Some fire-bricks in a very hot furnace will soften and melt 
away under long sustained heat. Others, more refractory or 
infusible, crack and split up under sudden temperature changes. 
A good brick becomes surface glazed, but the body remains 
rough and porous. A granular nature and porous structure 
are considered essential, and fire-bricks are not made of all new 
clay. Old bricks are granulated and mixed up with the new 
clay, so that the necessary texture is secured. 



70 LIQUID FUEL AND ITS APPARATUS 

Fire-clay is a mixture of silica and alumina in varying pro- 
portions, each constituent possessing its own peculiar charac- 
teristics. Usually silica exists in the proportions of about 
two-thirds to one-third of alumina. The presence of alkaline 
matter is prejudicial and induces fluxing. Thus lime is in- 
tensely refractory of itself, and so is magnesia, but both of these 
infusible substances fuse easily with silica, as also do oxides 
of iron, soda, potash and other alkalies. These impurities of 
fire-clays must be avoided. Mixing two clays of good quality 
will not necessarily prove a success. 

Silica, if otherwise pure, gives perhaps the most refractory 
bricks, and certain French fire-bricks are made from infusorial 
earth which consists of the minute siliceous shells of the diatom- 
acese. These French bricks, when dry, will float in water, their 
specific gravity being under 1,000, owing to the numerous 
voids and pores, but they are very tender and do not stand 
well at the fire-grate level, where a tougher and harder brick is 
necessary. The Dinas bricks of South Wales are very siliceous, 
but are liable to split up if suddenly cooled, and are therefore 
somewhat unsuitable for hand-fired furnaces, but should be 
excellent for mechanically-stoked furnaces with self-cleaning 
grates. Probably the best boiler furnace brick is one high in 
silica, yet containing a fair proportion of alumina and free from 
alkalies. Such a brick combines infusibility and toughness 
for puddling furnaces, coke ovens, gas retorts and other high 
temperature uses, and it must be remembered that the kind 
of furnace advised by the author for bituminous fuel com- 
bustion, and adopted from sheer necessity with liquid fuel, is 
exposed to temperatures more resembling those of metallurgical 
furnaces than the starved temperatures of the common un- 
scientifically set steam boiler. 

A sample of the clay from the Glenboig Star Mine, as analysed 
by Edward Riley, F.C.S., after calcination, gave the following 
results — - 

Per cenlj 

Silica 65-41 

Titanic acid 1-33 

Alumina 30-55 

Peroxide of iron 1-70 

Lime 0-69 

Magnesia 0-64 

Potash and soda • 55 



100-87 
Sir Frederick Abel analysed a Glenboig brick, at the Royal 



FIRE-CLAY AND FIRE-BRICK 71 

Arsenal, Woolwich, as follows. The brick was taken from 
stock — 

Per cent. 

Silica . . 62-50 

Alumina 34-00 

Iron peroxide 2-70 

Alkalies, loss, etc 0-80 

100-00 

Mere analysis, however, does not tell everything. For 
instance, in this last analysis the silica and alumina were largely 
in chemical combination, and this is more valuable than the 
mere mechanical combination of the constituents. 

To make a good brick the clay must be suitably weathered 
so that any iron nodules may separate out. The clay is ren- 
dered smoother and more solid for articles requiring such 
qualities, as seating blocks ; for high temperatures, porosity 
is given by the addition of old bricks. 

All defects of shape are produced in the drying stove after 
moulding. Stoving is therefore a most important operation, 
and a brick must be practically dry before firing, which is 
gentle at first until the bricks are hot and perfectly dried out. 
Then the kiln is put on to full fire, and the temperature must be 
maintained until the bricks cease to shrink. A brick which 
has not been fired at a full temperature will shrink further if 
put to work at a higher temperature. The total shrink from 
the moulded size is about 8J per cent, of the bulk, or about 2 
per cent, linear measure. In any case no shrinkage should 
remain in a brick, or it will shrink when put to work and pull 
the brickwork in pieces. 

Professor Abel, F.R.C., gave various analyses of fire-clays 
as per the annexed table, from which the excellence of Stour- 
bridge and Glenboig bricks is plainly evident in the small 
percentage of alkalies. 



Description of Fire-clay. 


Silica. 


Alumina. 


Iron 
Peroxide. 


Alkalies, 
Loss, etc. 


Kilmarnock 


59-10 


35-76 


2-50 


2-64 


Stourbridge 


65-65 


26-59 


5-71 


205 


>> 


67-00 


25-80 


4-90 


2-30 


» 


66-47 


26-26 


6-33 


0-64 


>> 


58-48 


35-78 


3-02 


0-72 


,, ..... 


63-40 


31-70 


3-00 


1-90 


Newcastle ..... 


59-80 


27-30 


6-90 


6-00 


55 ..... 


63-50 


27-60 


6-40 


6-50 


Glenboig 


62-50 


34-00 


2-70 


0-80 



72 



LIQUID FUEL AND ITS APPARATUS 



For the following miscellaneous information the author is 
indebted to the Glenboig Company — 



Shape and Size. 


Weight. 


Inches. 


Tons. 


1,000 Square Bricks 9x41x3 = 


4 


1,000 „ ... 






9x4ix2i = 


H 


1,000 „ . . 






9x4|x2Jr = 


3 


1,000 End or Side Arch 






9x4|x3 and 2 


3* 


1,000 






9x4|x2| and 1£ 


2| 


1,000 






9x41x3 and 2J 


3f 


1,000 Cupola .... 






9 x 41 and 3x3 


H 


1,000 Pup Bricks . . 






9x3 x2i = 


2 


1,000 „ . . 






9x2ix2i = 


If 


1,000 Scone Blocks . . 






9x4ix2 = 


2| 


1,000 „ . . 






9x4ixl| = 


2 


1,000 Crown or square . 






9x6 x3 = 


H 



One inch = Millimetres 25-4 



One Ton = Kilogrammes 1,016. 



Miscellaneous Weights and Measurements. 



STACKED LOOSE. 

1,000 9 in. x4i in. x2J in. =66 cub. ft. 
1,000 9 in. x4i in. x3 in. x3 in. =80 cub. ft 

BUILT WITH FIRE-CLAY. 

1 square yard 9 in. work requires : — 

109 bricks 9 in. x 4| in. x 2| in. and 2 cwts. ground fire-clay, or 92 bricks 

9 in. x4£ in. x3 in. and If cwts. ground fire-clay. 

A rod (English) of brick = 11 \ cub. yds. 

A rood (Scotch) of brick = 16 cub. yds. 

FOR PAVING. 

1 yard superficial requires 16 tiles 9 in. x9 in. 

18 tiles 12 in. x6 in. x2 in. 
32 bricks 9 in. x 4| in. x 3 in. laid flat. 
48 bricks 9 in. x 4| in. x 3 in. laid on edge. 
One 9 inchx4| in. x3 in. =9 lb. 
17| cub. ft. blocks = 1 ton. 
334 bricks = 1 load. 
1,500 to 2,000 = 1 railway truck. 
3,100 to 3,200 9 in. x4|x2| in. bricks = 1 railway truck (Continental) 
6 to 8 tons ground fire-clay = 1 railway truck. 
8 bags ground clay = l ton. 
3 casks ground clay = l ton. 
21 cub. ft. of dry ground fire-clay, firmly packed = 1 ton. 
Fire-clay suffers no deterioration of quality from rain. 
For shipment it is packed in barrels or bags. 
The usual shipping size of fire-brick is 9 in. x 4| in. x 2\ in. 

The Glenboig Company make special silica bricks from 
English chalk flints; they weigh 2 tons 12 cwt. per 1000, 



FIRE-CLAY AND FIRE-BRICK 



73 



9 in. X 4J in 



X 2J in. 



They also make a highly refractory 
brick from Gartcosh clay, which analyses as below, according 
to W. Wallace and Jno. Clark, Ph.D., F.C.S., etc.— 

Per cent. 

Silica 61-90 

Titanic acid 2-09 

Alumina 32-34 

Peroxide of iron 3-02 

Lime 0-37 

Magnesia 0-20 

Potash 0-06 

Soda . 0-30 



100-28 



The proportion of alkalies is thus small and the brick is 
solid and has small shrinkage from the mould and weighs 131 
pounds per cubic foot. The ganister bricks of the Company, 
which are made from what appears to be a soft sandstone, 
analyse as below — 





Gartcosh Ganister. 


Gartcosh Silica. 


Silica 

Titanic acid ...... 

Alumina 

Oxide of iron 

Lime 

Magnesia 

Potash 

Soda ......... 


87-06 
Trace 

11-24 
0-69 

Trace 

Trace 
0-61 
0-33 


74-10 
0-20 

22-32 
2-28 
0-48 
0-34 

0-38 




99-93 


100-00 



Bricks for Oil-fired Furnaces. 

Where bricks are applied to oil-fired furnaces the intense 
local heat of the oil furnace of course burns the brickwork 
away in time, or rather melts it on the surface immediately 
in contact with the flame, causing it to run down and hang in 
the form of stalactites, but it takes a considerable time to wear 
through nine inches of brickwork, and the cost of the bricks 
is more than compensated for in the increased efficiency of the 
furnace. 

It is often the case that furnaces and combustion chambers 
fined with fire-brick come to grief through being badly built 
rather than from the bad quality of the bricks used ; at the 
same time, good work will not make up for bad bricks. The 
usual type of liquid fuel furnace for kilns is as shown in the 



74 



LIQUID FUEL AND ITS APPARATUS 



annexed illustration, Fig. 1, the burner being so set that the 
fuel in vaporized form is more or less concentrated in the centre 
arch at x. The consequence is that the intense heat is 
localized and the brickwork runs down into slag. Various 
methods have been tried to get over the difficulty — one is to 
cover the grate with broken fire-brick, or coke, but this was not 
altogether successful. Another idea is to protect the piers 




of the arches with bricks piled up loosely in semicircular form, 
with the concave side facing the burner, stacking them with a 
space between, and crossing the open space with another row 
of bricks, as shown in plan, Fig. 2, thus distributing the heat 
over a large area of brick surface. 

The bricks would melt after a time, but they could be raked 
out and a fresh lot put in, and the arches would be saved con- 
siderably. 



C3^=3 




Fig. 2. 



In the case of over-fire arches, Fig. 3, for water tube boilers 
having a wide span, the best type of brick to use is what is 
known by the name of the Bullhead or End- wedge, as shown 
in Fig. 4, or the special bricks of Fig. 5. 

In all cases fire-bricks should be set with as little jointing 
material as possible, and for arches the bricks should be speci- 
ally made to work to the desired radius. Any attempt to use 



FIRE-CLAY AND FIRE-BRICK 



75 



\ 




• 




£L£ V ATiOKJ 



]■■■■■■■:.■-■.■/-. 








I 






1 



Fig. 3. 

ordinary rectangular bricks is fatal. The pressure becomes 
concentrated on the underside of the arch, as in Fig. 6, and the 
mass has no rigidity — bricks begin to fall out and the arch is 
ruined. 

The bricks should be set with finely ground fire-clay made 
up with water to the consistency of thick paint. The brick 
should be dipped in this, and then rubbed into contact with its 
neighbours. 

Fire-clay is made up into specially shaped bricks and lumps 
for different purposes, and bricks and blocks can be made to 
meet the special requirements in furnace work, but unequally 
proportioned lumps must be avoided on account of internal 
stresses, fire-clay having its limitations in this respect, as ex- 
plained above, just as cast-iron has The best plan is to con- 



76 



LIQUID FUEL AND ITS APPARATUS 



suit a reputable maker. The most usual course is to decide 
on all other points of construction and make the best job 




LARGE 





S MALL 





ARCH 6RICK 



SPRINGER 



possible on what are generally considered incidentals, such as 
furnace linings, whereas by taking the limitations of a necessary 
material into consideration in the first place, much expense and 

trouble may be saved. 

Good fire-bricks should 
have sharp angles, and 
give a metallic ring on 
being rubbed together. 
They should be kept some 
time before use in a dry 
place. Bricks sodden with 
rain and heated up quickly 
will tend to burst. 
Fig. 5. Various substances hav- 

ing been suggested as sub- 
stitutes for fire-brick, it may not be out of place to say 
something as to the varieties of fire-clay goods. 

The following is the classification generally adopted — 

I Siliceous fire-clay goods. 

II Aluminous „ „ 

III Argillaceous „ „ 

IV Carboniferous „ „ 

Nos. I and II are the 
most generally used. 

No. IV is a mixture 
of carbon and clay, the 
carbon being in a crys- 
tallized state as used 
for arc lamps, etc., or 
amorphous as graphite, 
the latter being used 
for the manufacture of crucibles, etc. Carbon blocks have 




Fig. 6. 



FIRE-CLAY AND FIRE-BRICK 77 

been suggested, but, apart from the excessive cost, the carbon 
combines with any free oxygen in the furnace gases and is 
consumed. 

No. II. A mixture containing a greater portion of alumina 
than pure clay. This also is too costly for general use. 

Lime is sometimes used as furnace lining for electrical kilns 
and will withstand the intense heat of the voltaic arc, but as it 
retains the property of being hydrated in air, its use is neces- 
sarily very limited. This class of fire-clay goods is known as 
basic. 

Siliceous fire-clay goods are composed almost exclusively of 
silica. 

Argillaceous fire-clay goods are composed of silica and alumina, 
and are next in degree of refractoriness to aluminous goods. 

It should be borne in mind that the foregoing are each 
adapted to particular purposes, and the proper admixture of 
clays for any desired purpose is a matter that only long experi- 
ence and scientific knowledge can determine, the physical as 
well as the chemical properties of clay having to be taken into 
account. 

Siloxicon. 

A very refractory material is Siloxicon, a product of the 
electric furnace, consisting of carbon, silicon and oxygen formed 
at a temperature of 4,000° to 5,000°F., and therefore very 
refractory at ordinary temperatures. It is a loosely coherent 
mass as formed and is ground to pass a 40 2 sieve. It is an 
amorphous grey-green compound when cold, becoming light 
yellow at 300°F. It is insoluble in molten iron, neutral to 
acid and basic slag, indifferent to all save hydrofluoric acid, 
and is unattacked by hot alkaline solutions. It is formed into 
bricks by simple pressure, when damp, and fired. It is neutral 
to clays and will not oxidize, and appear likely to form a valu- 
able furnace lining where oil fuel is employed. 



CHAPTER V 

COMBUSTIBLES AND SUPPORTERS OF COMBUSTION 

Carbon. 

CARBON is an element which has the following properties. 
Its atomic weight is 12 and it is tetravalent in chemistry. 
It is found free in nature in various forms, but is usually 
considered to exist only in three allotropic modifications, viz. — 

(1) The Diamond, which is practically pure crystallized 
carbon. 

(2) Graphite, not entirely amorphous. 

(3) Charcoal, an amorphous substance, is considered to 
include all other forms of carbon. 

The following figures give the values of the various forms 
of carbon in calorific value or heat absorption — 

COMBUSTION. 



State of 1 pound or 1 kilo, of Carbon. 

Diamond 

»» ••••••• 

Graphite 

Amorphous 

Ideal Gaseous 

,, ,, ...... 

2 \ pts. of CO per part of C. . 



Product of 
Combustion. 



Calories 
per kilo. 



B.Th.U. 

per pound. 



CO 

co 2 
co 2 

CO 

co 2 

CO 

co 2 



2,175 

7,859 
7,900 
2,453 
8,137 
5,684 +e 
11,370 +e 



3,915 
14,146 
14,222 

4,415 
14,647 
10,232 +e 
20,463 +e 



CO, 



5,683 



10,231 



HEAT ABSORBED BY METAMORPHIC CONVERSION. 



Diamond to 

Graphite 

Amorphous 

Diamond 



Graphite 




3,508 
3,468 
3,231 
41-5 
277-0 
235-7 



6,316 
6,241 

5,817 

74-7 

499-0 

424-3 



78 



COMBUSTIBLES AND SUPPORTERS 79 

The above figures are calculated from the determinations 
by Berthelot of the heat of combustion and formation of the 
molecule (see Thermochimie, par M. Berthelot, Paris, 1897). 

Except that these figures point the lessons that form and 
state are dependent upon heat, apparent or latent, no further 
interest centres on the crystalline modification of carbon, 
which is too scarce to employ as a commercial fuel. 

The first oxidation of ordinary carbon with one atom of 
oxygen to CO produces 4415 B.Th.U. =2,453 cal. per pound 
and per kilogram respectively. 

The second oxidation produces a further 10,231 B.Th.U.— 
5,684 cal. The total heat produced by complete combustion 
is thus 14,647 B.Th.U. =8, 137 cal. 

The difference (5,684 — 2,453) between the two oxidations 
is 5,817 B.Th.U.= 3,231 cal., and Berthelot considers that this 
difference is less than the latent heat of vaporizing carbon by 
some unknown amount. In the absence of a knowledge of 
what it amounts to, it is usual to say that the difference is the 
latent heat of valorizing carbon, just as 967 is the latent heat 
of steam. 

In order to liquefy, carbon must absorb heat, but free liquid 
carbon is unknown. Solid carbon burns directly to dioxide 
gas without going through the intermediate liquid state, 
exactly as a piece of ice will disappear in a dry cold wind below 
freezing temperature without passing through the intermediate 
state of water. The liquid state is not imperative, and carbon 
is only found liquid when combined with other substances. 
It forms a liquid with sulphur as carbon bisulphide CS 2 . It 
is liquid with hydrogen and oxygen in alcohol, and it is liquid 
with hydrogen alone in the many hydrocarbons with which we 
are at present concerned. By so much as the liquid form 
already represents heat rendered latent in reducing a solid to a 
liquid, by just so much should liquid fuel possess a greater 
calorific value per unit of its contained carbon than a similar 
weight of solid fuel. The same argument applies with equal 
force to the hydrogen, but to some extent conversely. The 
calorific capacity of hydrogen is given in terms of the gas 
burned as gas. In solid coal the hydrogen is part of a com- 
pound solid, and it is scarcely correct to calculate the calorific 
capacity of a solid fuel in terms of its hydrogen at gas value, 
for undoubtedly heat is absorbed in rendering the hydrogen 
gaseous from its solid combined state in coal. Similarly, in 
liquid fuel the hydrogen is in liquid form and must be gasified. 
It is possible that. the benefit derived from the liquidity of the 
carbon is neutralized by the liquidity of the hydrogen. 



80 LIQUID FUEL AND ITS APPARATUS 

The properties of carbon are summarized in the following 
table — 

Properties of Carbon. 

Atomic weight 12 

Specific heat 0-1468 to 0-285 

Heat of combustion per kilo, to C0 2 . 8,137 cal. =32,285 B.Th.U. 

„ „ „ „ pound to C0 2 . 14,647 B.Th.U. =3,691 cal. 

Temperature of vaporization . . . 3,600°C. =6,512°F. 
„ „ combustion to CO 

In air 1,485°C. =2,705°F. 

In oxygen . . . 4,292°C. =7,757°F. 

Air required to burn 1 unit to CO . . 5-797 

Oxygen „ „ 1 „ „ „ . 1-334 

1 „ „ C0 2 . . 2-667 

Air „ „ 1 „ „ C0 2 . . 11-594 

Temperature of combustion to C0 2 

In air 2,753°C. =4,988°F. 

In oxygen . ' 10,226°C. =18,440°F. 

Heat of combustion to CO 

per pound . . . '. . . 4,415 B.Th.U. =1,112 cal. 

per kilo 2,453 cal. =9,733 B.Th.U. 

Weight of vapour per cubic metre (ideal) 1-072 k. =0-06696 per cubic 

foot. 

The atomic weight of carbon being 12 and that of oxygen 16, 
the formula for carbon monoxide — CO tells that there are 12 
parts of weight by carbon in each 28 parts of the gas. Hence 
1 pound of carbon unites with Impounds of oxygen to produce 
2 J pounds of gas. 

When burned to dioxide = C0 2 there are 12 parts of carbon 
to each 32 parts of oxygen, and 1 part of carbon unites with 
2| parts of oxygen to produce 3| parts of gas. 

As oxygen is not available for combustion except in the form 
of air, and as it is not desired to produce CO, the essential 
figures to remember are that each unit weight of carbon demands 
a minimum of nearly 11*6 units of air. 

In the foregoing table the temperatures are those calculated 
on the assumption that the specific heat of the gases produced 
remains the same at all temperatures and that combustion is 
complete. Neither assumption represents actual facts, for the 
process of combustion is delayed as temperature rises, and 
even if it were not, the specific heat increases and holds back 
the temperature. Since in practice there are so many effects 
of dilution, the calculation of total heat can be correctly done 
on a basis of constant specific heat. If a final temperature of 
great intensity is found, a correction can always be applied 
after all calculation has been made. 



COMBUSTIBLES AND SUPPORTERS 81 

The various figures given in this book differ somewhat from 
many previously accepted figures, owing to the progress of the 
science of thermo-chemistry. The figures given herein are 
those given by Berthelot in his work, Thermochimie, 1897. 

Carbon burned to CO or directly to C0 2 does so with simple 
incandescence. No flame is produced. Carbonic oxide = CO, 
however, if formed by the burning of carbon with insufficient 
air, will burn with a blue flame if provided with air. 

The hydrocarbon gases burn with a reddish, a yellow, or a 
white flame, according to surroundings and temperature, the 
flame consisting of glowing carbon in an atmosphere of hot gas. 

Hydrogen. 

Hydrogen shares with carbon the monopoly of the term fuel, 
for there are no commercial fuels except carbon and hydrogen 
or their joint compounds. Hydrogen is a gas. Its atomic 
weight is 1, and being the lightest known element, it serves 
as the unit of atomic comparison. 

Its physical and other properties are as follows — 

Atomic weight and density .... 1 

Specific heat. Constant vol 24146 

„ ,, ,, pressure . . 3-410 

Weight per litre 0-08961 grams =0-000089 k. 

„ cubic foot 0-00559 pound = 0-002536 k. 

Cubic feet per pound 178-83=5,063-4 litres. 

Litres per kilogram 11,160 = 394-15 cubic feet. 

Heat of combustion per kilo. ) f 34,500 cal. =136,900 B.Th.U. 

pound [To0°C. ) 62,100 B.Th.U. = 15,650 cal. 

cubic foot | = 32°F.1 347 B.Th.U. =87-45 cal. 

litre J I 3-091 cal. =12-264 B.Th.U. 

Specific gravity, water = 1 .... 0-0714 when liquefied. 

Point of vaporization 33° abs. C. =60 abs. F. 

„ freezing or liquefaction . . . 16-7° abs. C. =30° abs. F. 
Temperature of combustion — 

(nominal) in oxygen . 6,762°C. =12,202°F. 

air. . . 2,513°C.=4 5 554°F. 
Ratio of air required to burn 1 unit weight 34-785 

„ 1 unit vol. . . 2-39 

„ „ „ oxygen weight . 8-00 

„ „ ,, oxygen vol. . . 0-50 
Heat of combustion per kilo, (result in 

vapour) 29,150 cal. =115,434 B.Th.U, 

Heat of combustion per pound (result in 

vapour) 52,290 B.Th.U. = 13,177 cal. 

The heat of combustion of hydrogen is 62,100 B.Th.U. per 
pound. This assumes that the products of combustion are 
rejected in a liquid state. In furnace work, however, the gases 
of combustion always leave at temperatures above 100°C, 



82 



LIQUID FUEL AND ITS APPARATUS 



and consequently the gases carry off with them the latent heat 
of evaporation. This reduces the available heat to 52,290 
B.Th.U per pound, or 29,150 cal. per kilogram, or say 293 
B. Th.U. per cubic foot and 2-612 cal. per litre. This fact must 
be borne in mind when calculating results. 

Smoke Production. — Hydrogen ignites at a temperature 
below that necessary to ignite carbon. Its affinity for oxygen 
is greater and, in presence of an insufficient supply of air, the 
hydrogen of a hydrocarbon fuel will first secure its share of 
oxygen and the carbon will appear as soot. Sudden cooling 
of a hot hydrocarbon gas is also said to produce soot, but it is 
questionable if soot is really produced without a certain amount 
of combustion of the hydrogen. 

The following table gives the temperature of ignition of a few 
of the hydrocarbon gases, according to Mayer and Munch — 



Marsh gas 
Ethane . 
Propane . 
Acetylene 
Propylene 



CH, 


667°C. 


1,232°F 


C 2 H 4 


616°C. 


1,141°F. 


C 3 H 8 


547°C. 


1,017°F 


C 2 H 2 


580°C. 


1,076°F 


G3H.6 


504°C. 


1,004°F 



Hydrogen burns with a transparent blue flame. Its com- 
pounds with carbon burn with a light-giving flame consisting of 
incandescent carbon particles carried in an atmosphere of gas. 

These hydrocarbons are exceedingly numerous, and range 
from gases of small density through every shade of liquid to 
solids like naphthalene and paraffin wax. 

The percentage of carbon and hydrogen in a petroleum of 
any degree of refinement does not vary far from 84 of carbon 
and 16 of hydrogen, corresponding with a mean formula of 
C7H16 



Air. 

Oxygen being necessary for combustion, there is only one 
source whence it can be obtained in large quantity, viz., the 
atmosphere. 

The atmosphere contains by volume — 

20-84 vols, of oxygen ) ,.* ., , 
» a , a ./ & ^ratie 1 to 3-8. 

79-16 „ „ nitrogen j 

There are also small quantities of other gases, the principal 
of which is carbon dioxide, C0 2 , present to the extent of only 
0-0004, and negligible for present purposes. 



COMBUSTIBLES AND SUPPORTERS 83 

By weight the atmosphere contains — 

23-15 parts of oxygen) ) { 
76-85 „ „ nitrogen/ 

The mean atmospheric pressure at sea-level is assumed by 
Rankine to be 14-704 pounds per square inch, at a temperature 
of 32°F. = 0°C. The mercury barometer then stands at 
29-922 inches. At this pressure water boils at 212°F. = 100°C. 
The metrical atmosphere also measured at 0°C. is 760 mm. 
of mercury column = 29-922 inches. At the ordinary tem- 
perature of 57-8°F. the mercury barometer of 30" = 1 atmo- 
sphere, and at all ordinary temperatures and for purposes of 
steam engineering it may be called 30 inches. 

Expressed in metric measures, one atmosphere is 1-0333 
kilos per square centimetre at Paris. 

A mercury column giving 14-704 at London will give 14-6967 
= 1-0333 kilos at Paris and 14-686 at New York. 

The pressure and density of the atmosphere varies with the 
elevation above sea level, and may be thus calculated — 
H = 60,000 (1-477-log R), where 
R is the elevation in feet above sea level ; 
H is the barometric height in inches at elevation R, and 1-477 
= log 30. 

Hi3h elevation requires consideration in regard to the relative 
volume of air for furnace supply. 

Air at all temperatures for purposes of furnace work behaves 
as a perfect gas. 

The weight of a cubic foot of dry air at 62°F. is 532-5 grains. 
If saturated with moisture the weight is 529 grains. The 
specific gravity of air is 819 times less than water, and one 
pound of air measures 13-146 cubic feet at 62°F. 

The standard barometric pressure of 1 atmosphere or 14-6967 
pound per square inch at Paris = 1-0333 k. per cm. is curiously 
approximate to 1 k. per cm 2 . or to 14-21 per square inch. 

Approximately 1 atmosphere is equal to a pressure of 1 k. 
per square centimetre. 

The density of air relative to hydrogen is 14-44, its specific 
heat is 0-2375 at constant pressure, and 0-1686 at constant 
volume. One pound of air measures 12-385 cubic feet at 0°C. 
:=32°F., and 1 cubic foot weighs 0-08073 pound. One litre of 
air weighs 1-292743 grams at 0°C. and 760 mm. 

Oxygen. 

Oxygen is the active constituent of the atmosphere in pro- 
moting combustion. It combines with most elements to form 



84 LIQUID FUEL AND ITS APPARATUS 

oxides with evolution of heat. The atomic weight of oxygen 
is 16 and it forms one stable oxide with hydrogen = H 2 (see 
Water) and two oxides with carbon, viz. — 

(1) Carbon monoxide or carbonic oxide = CO, which 

contains 12 by weight of carbon and 16 by weight 
of oxygen, and 

(2) Carbonic acid or carbon dioxide == C0 2 , containing 12 

by weight of carbon to 32 of oxygen. 

The density of oxygen is 16 ; its weight per cubic foot is 
0-08926 pound at 0°C. = 32°F. and 11-203 cubic feet weigh one 
pound. 

Its specific heat at constant pressure is 0-217 and at constant 
volume 0-1548. One litre of oxygen at 0°C. and 760 mm. 
weighs 1-4293 grams. 

Nitrogen. 

This gas constitutes about four-fifths of the atmosphere. 
It is a colourless gas and very inert. It does not support com- 
bustion, but acts by dilution to restrain its intensity and to 
reduce the temperature. 

Its density is 14, specific heat = 0-244 at constant pressure, 
and 0-173 at constant volume. It weighs 0-07845 per cubic 
foot and 1 pound equals 12-763 cubic feet. One litre of nitrogen 
weighs 1-2505 grams at 0°C. and 960 mm. 

The weight of nitrogen in the atmosphere is 3-32 times that 
of oxygen. It is, therefore, the cause of much dilution of the 
products of a furnace, and reduces the theoretical temperature 
of combustion to a figure much below that of combustion in 
oxygen. 

Water and Steam. 

Steam is produced by heating water to such a temperature 
that the elasticity of the water vapour becomes greater than 
the superincumbent air pressure of about 14-7 pounds per 
square inch at the level of the sea. (See Air.) 

Pure water is not found in nature, but is closely approximated 
in sain caught on hill-tops distant from towns, and in streams 
which flow off the barren country associated with granitic rocks, 
the millstone grits, and certain other geological strata. Water 
is an oxide of hydrogen, and its chemical formula is H 2 0. It 
consists of 2 parts by weight of hydrogen to 16 parts of oxygen, 
and it is produced when hydrogen is burned, the combustion 
setting free a large amount of heat. (See Hydrogen.) 

Water is used as the unit point in many physical data. The 
specific gravity of all other substances is referred to that of 



COMBUSTIBLES AND SUPPORTERS 



85 



water as unity. So also is the specific heat of all other sub- 
stances, and excepting hydrogen, the specific heat of water is 
the highest of any known body. The amount of heat necessary 
to raise the temperature of 1 kilogram of water from 0°C. to 
1°C. is called the great calorie or simply the calorie, the little 
calorie having reference to the weight of one gram only, and 
being employed by chemists and physicists. 

Similarly the heat necessary to raise the temperature of 
one pound of water from 32°F. to 33°F. is called the British 
Thermal Unit or B.Th.U. Thus 1 calorie = 3-9683 B.Th.U. 
and 1 B.Th.U. = 0-252 calorie. 

Weight. 

One gallon of pure distilled water at 62°F. weighs 10 pounds 
by Act of Parliament. The American or old wine gallon 
weighs 8 J pounds and measures 231 cubic inches, as com- 
pared with the British Imperial 10 lb. gallon of 277-479 cubic 
inches (Chaney). One cubic decimetre of water or 1 litre 
weighs, by law, 1 kilogram, the kilo, being 2-204 pounds. 
Thus 1,000 k. weigh very nearly 1 ton. 

A column of water 1 foot high exerts a pressure at the base 
of 0-434 pounds per square inch. Thus a pressure of 1 pound 
per square inch represents a column of 2-3 feet. Hence an 
atmosphere of pressure is equivalent to 33-8 feet of water 
column. 

Compressibility. 

Water is nearly incompressible, the coefficient at 0°C. — 
32°F. being -000052, and at nearly 53°C. = 127°F. = 0-0000441. 
It is thus negligible. 

Expansion. 

Water changes its volume with change of temperature, but 
not to an amount that is of serious account in steam engineering. 



Temp. 


Weight. 


Temp. 


Weight. 


Temp. 


Weight. 


212°F. 

250 
300 


59-71 

58-81 
57-26 


350° 

400 

450 


55-52 
53-64 
50-66 


500° 

550 

62 


49-61 

47-52 
62-2786 


102 


62-00 


158 


61-00 


203 


6000 



The foregoing table gives the weight per cubic foot of water 



86 



LIQUID FUEL AND ITS APPARATUS 



at various temperatures, showing that the maximum expansion 
in the open air does not reach 5 per cent. 

Water attains its maximum density at 4°C. = 39-l°F. 

It becomes solid at a temperature of 0°C. = 32°F., the freez- 
ing point of water being employed in fact as the 0° of the 
Centigrade thermometers. 

Ice has a specific gravity of 0-922 and a specific heat of 0-504. 
To reduce 1 pound of ice at 32°F. = 0°C. to water also at 
32°F. requires 142 B.Th.U. = 35-78 calories. The latent 
heat of water is thus said to be 35-78 calories or 142 B.Th.U. 
per pound, or 78*86 calories per kilogram. 



Specific Heat. 

The specific heat of water, called 1-00 at 0°C. = 32°F., is 
not uniform, but increases slightly with increase of temperature, 
as per the following table : — 



Temp. F. 


Specific Heat. 


Temp. F. 


Specific Heat. 


32° 


10000 


248° 


10177 


50 


1-0005 


266 


10204 


68 


1-0012 


284 


10232 


86 


1-0020 


302 


10262 


104 


10030 


320 


1-0294 


122 


10042 


338 


10328 


140 


10056 


356 


10364 


158 


1-0072 


374 


1-0407 


176 


1-0089 


394 


10440 


194 


10109 


410 


10481 


212 


10130 


428 


10524 


230 


10153 


446 


10568 



As at the above temperature the bulk of water is increased 
in a much greater ratio than the specific heat, the total heat 
per cubic foot will decrease somewhat with rise of temperature. 

As the total heat contained in one pound of steam measured 
from 32°F. is nearly 1,200 B.Th.U., this amount of heat is 
more or less thrown away when steam is used to atomize liquid 
fuel. The gases never leave a furnace below 212°F., and every 
pound of steam carries off its load of 967 units of latent heat 
to the chimney. Air being already a gas, and necessary to 
combustion, causes no loss in this manner, but it requires 
power to compress air, and some steam is thereby used, but, 
especially at sea, such steam can be condensed and does not 
therefore lead to a loss of fresh water. No extra work is 



COMBUSTIBLES AND SUPPORTERS 87 

thrown upon the evaporation plant. Water may be split up 
by heat into its two constituent gases. In this process of 
dissociation or decomposition exactly as much heat is absorbed 
as was produced by the combination of the gases when the 
water was formed. This plain chemical fact is ignored by 
those who dream of steam as fuel, and imagine that steam jets 
introduced into a furnace will decompose and burn with any 
effect in increasing the total heat production of the furnace. 
Steam thus employed is useful as a mechanical draught pro- 
ducer only, or there may be some truth that hydrocarbons 
burn better in the presence of moisture. But no further 
claim is tenable. 



Useful Figures. 

In the calculations of the steam engineer it is convenient to 
remember that the square of the diameter of a pipe or a pump 
barrel gives the weight of water in a yard length of pipe. Thus 
a six-inch pipe holds 36 pounds or 3-6 gallons per yard. Again, 
1 pound of coal should evaporate 1 gallon of water ; 1 gallon 
of water will give steam to work in the best engine yet made 
at the rate of 1 h.p. hour. Two gallons will serve an ordinary 
compound engine per h.p. hour, and 3 gallons a good non-con- 
densing engine for each h.p. hour. Approximately, too, 1,000 
B.Th.U. generated represents one pound of steam, so that the 
number of thousands of units capacity of a pound of fuel 
represents the theoretical evaporation in pounds of water. 



Solubility of Salts. 

As a rule this increases with the temperature, but at a slow 
rate, except for sodium chloride and a few other exceptions. 
For the sulphates of magnesium and potassium and the chlorides 
of barium and of potassium, solubility is proportionate to the 
increase of temperature. 

With sulphate of soda the solubility first increases and then 
falls off again. 

The solubility of calcium sulphate decreases with tempera- 
ture. 

The following table gives the solubility of a few salts at various 
temperatures in parts per 100. 

The solubility at 212°F. is really at a higher temperature, 
being the solubility at boiling point, which is always raised 
slightly by the solution of a salt. 



88 



LIQUID FUEL AND ITS APPARATUS 













Temperature. 




32°F. 


70°F. 


212°F. 


Calcium chloride 


4000 


— 


— 


Magnesium sulphate 










24-7 


350 


130-0 


Potassium carbonate 










100-0 


80-0 


— 


„ chlorate 










3-33 


8-0 


60-0 


„ chloride 










29-21 


34-0 


60-0 


„ nitrate . 










13-32 


300 


240-0 


„ sulphate 










— 


120 


26-0 


Sodium carbonate . 










6-97 


21-7 


451 


„ bicarbonate 










6-9 


9-6 


— 


„ chloride 










35-5 


360 


39-6 


„ sulphate 










5-02 


220 


42-6 


Barium chloride 










350 


— 


600 


Calcium carbonate . 










•0036 


— 


— 


„ sulphate 










•23 


— 


•21 


Magnesium chloride 










200-0 


— 


400-0 


„ carbonate 










•02 


— 


' — 



Sea Water. 

Sea water contains 38 parts per 1,000 of dissolved matter ; 
of this from 25 to 28 parts are common salt, NaCl. 

The Black Sea contains only 17-7 parts, the Caspian Sea 14*0, 
and the Baltic 6*7, owing to the large fresh water rivers which 
flow into them. The other salts of sea water are magnesium 
chloride, calcium sulphate, magnesium sulphate, potassium 
sulphate and chloride, bromide of soda, the carbonates of lime 
and magnesia, and traces of other salts and organic substances. 

Hardness. 

By this term is meant 1 grain per gallon of lime carbonate, 
CaC0 3 . Temporary hardness is that which can be reduced by 
boiling. Permanent hardness is not reduced by boiling. 
Water is softened by chemical means. 1 

Pipes. 
The ordinary velocity of flow in water in pipes may be taken 
at 72 inches per second. This velocity is to be reduced 1 inch 
per second for each 20 pounds pressure. Thus in feed pipes 
at 160 pounds pressure, the velocity will be 72 — 8 = 64 inches. 
Practical considerations demand, except where several boilers 
are fed through one pipe, that the pipes should be much larger 
than would give such a velocity in many cases. 

1 See Water-Softening and Treatment, by the Author ; Constable & 
Co. See also Liquid Fuel and its Combustion, by the Author; 
Constable & Co. 



COMBUSTIBLES AND SUPPORTERS 



89 



Pipes less than 1J inches are rarely advisable for feed pipes, 
and if pipes are liable to be scaled up they ought to be made 
initially larger than necessary to allow of a considerable deposit 
of scale without unduly diminishing their capacity. 



Useful Data regarding Water, 



gallon 

American gallon 
cubic foot . 

gallon 

American gallon 

litre 

foot column 

pound per square inch 

gallon 

pound 

cubic foot . 

ton 



(Diameter of pipe in inches y 



1°C. per kilogram. 
1°F. per pound . 
Specific heat at 0°C. 

„ Ice . . 
Specific gravity at 0°C. 

Ice . 
1 atmosphere 



10 pounds. 

8-321 pounds. 

62-2786 lb. 

277-479 cubic inches. 

231 cubic inches. 

2-204 pounds. 

0-434 per square inch. 

2-304 feet head. 

1606 cubic feet. 
001606 „ 
00278 ton. 
35-97 cubic feet. 

Pounds per yard nearly of 
water contents. 

1 calorie. 
1 B.Tb-U. 
1-00. 
0-504. 
1000. 
0-922. 

33-8 feet of water. 



One pound of oil requires about 15 pounds of air for its 
chemical combustion, or about 207 cubic feet. 

Approximately this is 2,000 cubic feet of air per gallon of 
oil. 



CHAPTER VI 

CALORIFIC AND OTHER UNITS 

Thermo-Chemistry. 

THE subject will only admit of slight treatment in a work 
of this description. It has been exhaustively treated 
by Berthelot, especially in his Thermochimie of 1897 ; therein 
he gives the thermal equivalent of almost all known hydrocarbons 
and other elements and compounds. When the calorific cap- 
acity of a fuel is tested it will often be found to depart from 
expectation. Two fuels may have the same composition, yet 
produce very different effects. Thus acetylene and benzene 
have exactly the same ratio of hydrogen to carbon in their 
composition, their formula being C 2 H 2 and C 6 H 6 but their atoms 
are differently put together, and they produce very different 
amounts of heat when burned. Acetylene is very much more 
endo thermic than benzene, that is to "say, it actually absorbs 
heat when first compounded, and this latent heat adds to its 
calorific output when burned. Benzene and ethylene are 
also endo thermic, but the other fuel hydrocarbons and alcohol 
are exothermic, and having given out heat when formed they 
give out correspondingly less when destroyed by combustion. 
Thermo- chemistry teaches us to consider all substances from a 
monistic point of view, seeing in every gas latent heat to 
preserve it as a gas, without which heat it would fall to the state 
of a liquid. Similarly, we recognize that latent heat prevents 
liquids becoming solid. 

We realize that the conversion of solid coal into gas, such 
as occurs when coal is burned, demands an enormous heat 
absorption. Thus it is that the first oxidation of solid carbon 
to monoxide develops less than half the heat of the second oxi- 
dation. The same or even more heat is developed by the first 
oxidation, but disappears in changing the solid carbon and 
solid hydrocarbons into gas. We are enabled to appreciate 
the difficulties that stand in the way of perfect combustion 
of bituminous fuels, when we perceive the heat absorption of 
the gasification they endure before they burn. Thermo-chemis- 

90 



CALORIFIC AND OTHER UNITS 91 

try points out why the calorific capacity of liquid and of gaseous 
fuels is better than of solid fuels ; it teaches us to study the 
phenomena of specific heat, and helps us to understand and 
account for an infinite variety of apparent inconsistencies 
and to clear away the mists from our earlier views. As, how- 
ever, in engineering we can only deal with approximations, 
it is sufficient for ordinary purposes to base most calculations 
on approximations, and it is useful to be able to calculate the 
approximate expectation of calorific capacity of a fuel of any 
type. The formula of the French chemist Dulong may still 
be employed as substantially accurate. It is — 

Calories = x = 8,080C + 34,500(H - -J) where C = weight 
of carbon, H = weight of hydrogen and = weight of oxygen 
in 1 kilo, of the fuel ; or, if expressed in British Thermal Units, 
B.Th.U. — x — 14,500C + 62,100(H - f ), where x — the 
thermal units, C = the weight of carbon, H = the weight of 
hydrogen, and = the weight of oxygen in one pound of the 
fuel. 

The Verein Deutscher Ingenieure use a modified formula — 

x — 8,100C + 29,000(H - %) + 2,500S - 600E, thus allow- 
ing for the sulphur and for the hygroscopic water and for the 
fact that the hydrogen products are produced as steam. 

Mahler found an average of 44 fuels as follows — 

_ 8,140C + 34,500H - 3,000(0 + N) } 
X ~ 100 

which in B.Th.U. becomes when simplified — 
x — 200-5C + 675H - 5,400. 

Calculation has now given way to actual measurement of a 
sample in the Berthelot bomb or other form of calorimeter. 

We learn from thermo -chemistry why it is that the latent 
heat of steam diminishes with higher pressure, realizing that 
the difference is due to the absence of performance of external 
work. 

A few of the leading particulars referring to the gases most 
related to power engineering are re-tabulated in Table 5 from 
the author's more extended table in Kempe's Year Book. 

As a science thermo-chemistry recognizes no fuel as such. 
It has regard merely to the heat effects of chemical combi- 
nation. Combustion is usually restricted to carbon and hydro- 
gen, simply because these are the two substances we find in 
Nature on a sufficiently large scale to burn by means of the 
atmospheric oxygen. Both produce harmless gases, namely, 
steam and carbonic acid. Neither will support life, but they 
are not poisonous. 



92 LIQUID FUEL AND ITS APPARATUS 

By aid of thermo-chemical researches we learn that the 
various hydrocarbons have either absorbed or given off heat 
when they combined. If the former, they are said to be endo- 
thermic, if the latter exothermic. We learn to make allowance 
for the different states of fuel, and to realize that a gas ought 
to be superior to the same relative proportions of liquid fuel, 
and this again to solid fuels. But methane, CH 4 , is a gas, and 
yet it producess when burned an amount of heat less than it 
ought to produce, seeing that its hydrogen is still gaseous and 
its carbon is also gaseous. Instead of about 14,728 units of 
heat, it produces 13,343 units only, despite the benefit of 
vaporization of its carbon. 

The explanation is that when its elements combined they 
gave out actually more heat than was necessary to vaporize 
the carbon, and the excess of heat was dissipated at the time, 
and before methane can burn with oxygen, its constituents 
must be separated by means of heat. The heat necessary to 
do this reduces the heat of combustion. The different behaviour 
of acetylene arises from its absorption of heat in formation, 
such heat becoming apparent when the gas is burned. 

Heat. 

We do not know what heat is, but we know its effects, and we 
assume it to consist in atomic or molecular vibrations. 

The effects of heat, as they are apparent to our senses or to 
our reasoning powers, are variously named. First may be 
placed temperature. When a body is hot it can communicate 
heat to bodies at a less temperature. Temperature and quan- 
tity of heat have no particular relation to each other. A pound 
of lead may be hotter or have a higher temperature than a pound 
of iron or of water, and may be able to part with heat to those 
bodies. Yet it may possess much less quantity of heat, because 
lead has a lower specific heat. 

The same substance in two different states at the same tem- 
perature, as ice at 32° and water at 32°, possesses a different 
amount of heat in these two states. The difference is expressed 
as latent heat, and quantity of heat generally is expressed as 
units of heat, and we speak of the heat of combustion and the 
mechanical equivalent of heat, and must therefore define all 
these. 

Temperature. 

The boiling point at which the 212° of the Fahrenheit ther- 
mometer is fixed is that of pure water under the mean atmo- 



CALORIFIC AND OTHER UNITS 93 

spheric pressure of 14- 7 pounds per square inch. The Centigrade 
thermometer is marked zero at the temperature of melting ice 
and 100° at the boiling point, the atmosphere being the pressure 
of 760 millimetres of a mercury column. Thus 1°F.=|- of a 
degree Centigrade. The mercury thermometer is available from 
40°F.to 600°F., and even higher if the upper part of the tube be 
filled with compressed nitrogen. For higher temperatures it is 
necessary to employ pyrometers, which act by recording the 
difference of expansion of diverse metals or the pressure of 
heated air, or by electrical means. Metallic thermometers 
are not very satisfactory. In steam engineering, temperatures 
are met with from 32° to 600°F. in the engine-room, from 350° 
to 3,000°F. between the chimney and the furnace. By tem- 
perature is meant that state of a body due to heat, in which 
the said body can transfer heat to other bodies of less tem- 
perature. Temperature is a heat effect apparent to the sense of 
touch, and only by temperature can heat be transferred from 
one body to another, and the transfer is always from the hotter 
body to the less hot body. In this way heat can be transferred 
from a body containing less actual heat to one that contains 
more heat. Thus a mass of one pound of iron heated to a tem- 
perature of 132°F. contains 12-98 heat units. A similar mass 
of water at a temperature of 82° contains 50 heat units, the 
heat content being in each case measured from a datum of 
32°F. Yet if we immerse the iron in the water, heat will leave 
the iron which contains so little heat and will enter the water 
that contains so much heat, and will raise the temperature of 
the water. A clear distinction must be made between tem- 
perature and quantity of heat. Temperature can be measured 
by a thermometer, but specific heat can only be ascertained by 
equalizing the temperature of the substance whose specific 
heat is sought with that of a mass of water. The final tempera- 
ature enables the specific heat of the substance to be compared 
with that of water. 

There are three thermometric scales, namely — 

The Celsius or Centigrade, which divides the distance between 
freezing and boiling of water at sea level into 100 degrees, the 
freezing point being 0°. 

The Reaumur scale, still much used in Russia, divides the 
same distance into 80 parts, also starting from 0° = freezing 
point of water. 

The Fahrenheit scale divides the same distance into 180 
parts, but starts the zero mark at 32° below freezing. Hence 
the boiling point is 212°. It is frequently necessary to con- 
vert one reading to another. The following are the formulae 



94 LIQUID FUEL AND ITS APPARATUS 

for doing so, C, R. and F. being the respective readings on 
each scale. 

To convert C. to R. — 



C.° x £ = R.° 




To convert R. to C. — 




R.° x| = C.° 




To convert C. to F.— 




(C.° X f ) + 32° 


= F. 


To convert F. to C. — 




(F.° - 32°) x f 


= C. 


To convert F. to R. — 




(F.° - 32°) x | 


= R. 



To convert R. to F. — 

(R.° xf) + 32°=F.° 

It is particularly necessary not to forget the addition or sub- 
traction of the 32° of the Fahrenheit freezing point when con- 
verting temperatures, but it is also necessary to remember not 
to do so when converting mere statements of differences of 
temperature. Thus if water is cooled 50°C, this means it has 
been cooled through 90°F., not through 90° + 32°. This point is 
often confused by writers and leads to very erroneous statistics. 

By temperature we thus understand that a body in a certain 
state is in a certain condition of molecular vibration. Different 
bodies are differently affected by heat. Some bodies are placed 
in the state of molecular vibration known as temperature with 
less heat than others. Thus water requires more heat than 
any other substance, excepting only hydrogen. The relative 
amounts of heat to place bodies in a given state of vibration are 
called their capacity for heat or specific heat. 

In Table VI are given a few characteristic temperatures. 

Furnace temperatures can now be measured by the Fery 
radiation pyrometer. This instrument is stood at any con- 
venient and comfortable distance from the furnace, and the 
hottest of furnaces may thus easily be measured. The in- 
strument is not exposed to high temperature, though it measures 
this from its distant standpoint. It can be obtained, with 
explanation of use, from the Cambridge Scientific Instrument Co. 

Specific Heat. 

By specific heat is meant the number of heat units necessary 
to raise 1 pound of a substance 1° Fahrenheit, and as water 
has the highest specific heat of any solid or liquid, it is taken 
as the basis. The specific heat of water is measured at the 
temperature of maximum density, 39 1°F., by some writers, 



CALOKIFIC AND OTHER UNITS 95 

including Rankine, but 32° is probably more usual. The 
difference is unimportant. The specific heat of all bodies 
increases slightly with increase of temperature, a fact due to 
the increased molecular movement, and there is often very 
considerable difference between the specific heat of the same 
body solid and liquid, notably in the case of water, the specific 
heat of ice being only 0-504°. 

Since 1 pound of water requires 1 unit of heat to raise its 
temperature 1°, its specific heat is thus said to be unity. All 
other substances are referred to water as a basis. Thus when 
we say that lead has a specific heat of 0314, we mean that to 
heat a pound of lead to a certain temperature only requires 
about 3 per cent, of the amount expressed in B.Th.U. that 
would be required to raise the temperature of an equal weight 
of water by the same amount. It is necessary to know the 
value of the specific heats of brick, iron, fuel and its products, 
in order to calculate pyrometric effects, furnace temperatures, 
etc. For the purpose Table VII of specific heats will usually 
serve. More extended tables are found in most pocket-books. 

Gases have two specific heats ; that at constant volume 
and that at constant pressure, the latter being greater and due 
to the work done in expanding to constant pressure. Table VII 
gives the specific heat of the more usual gases met with in 
combustion. 

The specific heat of all substances appears to increase with 
heat, more especially in the case of the gases. This is not of 
much importance in boiler work, but is considerable in gas 
engine research. In high temperature work the increase 
must be considered, but no error is introduced by neglecting 
the change when results are finally stated at low temperatures. 
The increase of specific heat with temperature is most marked 
in the case of the more easily liquefied gases. 

Specific heat, then, is the relative amount of heat necessary 
to give to bodies a given temperature. The specific heat of 
other bodies is stated as the fraction of unity relative to water. 
Most substances about a furnace, as fire-brick, have a specific 
heat of about 0-2. The total heat in a body is the product of 
its mass, its temperature and its specific heat as compared 
with some substance at another temperature and in the same 
state physically. Thus ice, water and steam which are 
chemically identical, differ in their physical states and cannot 
be so compared. The specific heat of ice is only about 0-504, and 
that of steam is 0-480. Ice at 32°F. may have heat added to it 
until it becomes water at 32°F. 

Water at 212°F. will absorb heat and become steam at 212°F. 



96 LIQUID FUEL AND ITS APPARATUS 

In both these cases we see no change of temperature due to the 
additional heat, but we see a change of physical condition. 
One pound of ice has absorbed 142 B.Th.U. of heat to enable 
it to exist as water. Any further heat then added will increase 
the temperature until 212°F. is reached. Then we may add 
966-7 B.Th.U. to the water with no change of temperature, 
but we get the water in the still higher physical state of steam. 
In each case the heat has become hidden or latent. It is not 
apparent as temperature, but is occupied in keeping the molecule 
liquid or gaseous, as the case maybe. Heat which thus, disap- 
pears in changing the state of a body is termed latent heat. 

Latent Heat. 

Latent heat is thus the heat enquivalent of the changed 
state of a body. It is not stated, however, as is specific heat, 
in terms of the ratio to water, but in actual heat units per unit 
of weight, as in calories per kilogram or B.Th.U. per pound. 
Thus the latent heat of water is said to be 142-6, because the 
melting of 1 pound of ice demands 142-6 B.Th.U. It is impor- 
tant to know the latent heat of a few substances. Some are 
given in the table below, those marked * being hypothetical 
and not definitely determined. 



Ice to water, both at 32°F 

Water to steam, 212°F. 

Carbon to gas 

Oxygen to gas * . 

Hydrogen to gas * . 

Nitrogen to gas *. 

Water to gas (H 2 dissociated) 1 



Per Pound. 



B.Th.U. 



142-6 
966 

5,817 
444 

7,320 
521 

6,900 



Cal. 



35-93 
243-3 

1,466 
111-9 

1,845 
131-3 

1,739 



Per Kilo. 



Cal. 



792 

536-4 
3,231 

246-7 
4,066 

289-4 
3,833 



B.Th.U. 



3143 

2,128 

1,282 

978-4 

16,130 

1,148 

15,210 



Heat becomes latent not merely by such a process as actual 
boiling of water. It becomes latent equally when water is 
converted to vapour by absorption in dry air : the heat must 
come from somewhere in such a case, and it comes primarily 
from the air or from the wooden floor on which water has been 
sprinkled for cooling purposes. If steam be heated above its 
saturation temperature, it will now only absorb about 0-480 
of a unit. Hence the specific heat of steam is barely half that 
of liquid water. After a very considerable further addition 
of heat, a point is reached where the temperature again ceases 
to rise ; but again here is a change of state. The water is 



1 From solid condition in coal. 



CALORIFIC AND OTHER UNITS 97 

split up into constituent elements of oxygen and hydrogen, 
and one pound of steam will absorb 6,900 thermal units during 
the splitting up of its chemical affinities, showing the great 
energy of chemical changes, for to melt ice requires 142 heat 
units per pound ; to vaporize the water requires 966-7 heat 
units, and to decompose it demands 6,900. No matter how 
it occurs that a body change its state, heat is given out or 
absorbed. To set free the solid hydrogen or solid water locked 
up in a piece of coal demands heat which is rendered latent. 
Thus heat is rendered latent when carbon is vaporized, and 
when again carbon is reduced from its state of carbonic acid gas 
to the solid form of wood by the action of the living forces of a 
tree, the heat is again set free by the solidification of the carbon ; 
but the heat rendered latent in the decomposition of a body 
is known as the heat of dissociation, and, like latent heat, is 
expressed in actual heat units. 

Dissociation. 

The heat absorbed in any process of chemical dissociation 
is an exact equivalent of the heat which is set free when the 
same substances combine. Thus if 1 pound of hydrogen unite 
with 8 pounds of oxygen to produce 9 pounds of water, the 
heat of combination is 62,100 B.Th.U., and therefore the heat 
of dissociation of water is 62,100 ~ 9 =6,900 B.Th.U. 

There now remains to consider only the 

Unit of Heat. 

The unit of heat is merely an arbitrary measure of comparison. 
In British measures it is the amount of heat necessary to raise 
the temperature of 1 pound of water through 1°F. at or near 
32°F. 

In the metric system it is the amount of heat necessary to 
raise the temperature of 1 kilogram of water through 1°C. 

As 1 kilogram =2-204 pounds and 1°C. =t°F. the ratio of 
the two units is 2-204 x 9-f-5= 3-968, the reciprocal of which 
is 0-252. 

The British Thermal Unit is written B.Th.U., and the metric 
unit is called the calorie and is written cal. Therefore 1 cal.= 
3-968 B. Th.U., and 1 B.Th.U.= 0-252 cal. For near approxi- 
mation the ratio of 4 : 1 may be employed. 

The heat unit is employed to express latent heat of com- 
bustion or of dissociation. 

It is necessary to have a statement of the relation of the heat 
form of energy and the unit of mechanical work. 

G 



98 LIQUID FUEL AND ITS APPARATUS 

Unit of Work. 

The unit of work is expressed in the form of the earth's 
attraction. 

For the purpose of the engineer the attraction of the earth 
is measured by the pull exerted at sea level in the latitude of 
London upon a piece of metal which is called the pound. The 
work done in lifting one pound through a height of one foot is a 
unit of work and is called the foot pound. Heat and mechanical 
work are mutually convertible. Dr. Joule, of Manchester, by 
the agitation of water by means of falling weights, ascertained 
that the unit of heat or B.Th.U. is the equivalent of 772 pounds 
raised one foot, or 772 foot pounds at the latitude and elevation 
of Manchester, and, with very slight variation, of no account in 
engineering, at any spot on the earth's surface. Joules' deter- 
mination of 772 was made by means of thermometers less 
perfect than those now procurable, or his figure would have 
been 778 foot pounds, as since found by Rowland. 

The mechanical equivalent of 772 foot pounds per degree 
Fahrenheit becomes 1,389*6 foot pounds per degree Centigrade. 

Expressed in terms metrical altogether or in kilogram 
Centigrade units, the equivalent is 3,063-54 foot pounds or 
423-55 kilogram metres. 

Thus the calorie is 423-55 km. = 3-968 B.Th.U. 

With the more modern figure of 778 foot pounds = 1 B.Th.U. 
=3,087-3 foot pounds. Per calorie = 426-84 kilogram metres, 
so that 1 B.Th.U. =107-78 metre kilograms. 

Weight. 

Like the British pound, the kilogram is simply a piece of 
metal, and work units are done in raising it against the pull of 
gravity. Hence the kilogram metre, whose relation to the foot 
pound is 7-231 : 1. 

The kilogram is 2-2 pounds (actually 2-2046212). The pound 
is thus 0-4536 kilos. 

The metre or unit of length is 39 370432 inches, or say 3 feet 
3 inches, and f very nearly for easy remembrance and mental 
calculation. 

Errors in converting units are most likely to occur when units 
are compound, as when converting pounds per square inch to 
kilos per cm. 2 

Very closely the English ton of 2,240 pounds resembles the 
French tonne of 1,000 k. =2,204-6 pounds. 

Also 1 k. per linear metre is equal nearly to 2 pounds per 
linear yard, and 9 calories per cubic metre is very closely 
1 B.Th.U. per cubic foot. 



CALORIFIC AND OTHER UNITS 99 

Gravity. 

Gravity = G at Greenwich is 32 19078 feet per second 
acceleration per second, usually written 32-2 per sec 2 . 

The expression -\/2G may be approximated as 8. 
Metrically, G = 9-8117 metres per second 2 at Greenwich. 
The true value at any other latitude (L), in centimetres per 
second 2 is — 

980-6056-2-5028 Cos 2 (L)-0 000003 H, 

where H is the height above sea level in centimetres. 
Other compound units that are useful are as follows — 

1 B.Th.U. per sq. ft. = 2-713 cal. per square metre. 
1 ,, ,, pound = 0-556 cal. per kilogram. 

To find the number of cubic feet of air at 62 °F. chemically 
consumed for one pound of fuel, take the percentage of carbon, 
hydrogen and oxygen in fuel. To the carbon add three times 
the hydrogen and subtract four- tenths of the oxygen and 
multiply the remainder by 1-52. The product is the cubic 
feet of air (A). 

Thus A =1-52 (C + 3H-04 O). 

The weight of air per cubic foot is pounds, or 13* 14 cubic 

13' 14 

feet= 1 lb. 

The total weight of gaseous products per pound of fuel is 
found by multiplying the percentage of carbon by 126 and 
that of the hydrogen by 0-358. The sum gives the total gases 
(W), thus W =0126 C + 0-358 H. 

The total volume is found by multiplying the carbon 
percentage by 1-52 and the hydrogen by 5 52 ; the sum of 
these is the total volume (V) in cubic feet at 62°F., thus 
V = 1-52C + 552 H. 

The volume at any other temperature (T) is V' = 

T + 461 
523 ' 

The Calorific Power of Fuel. 

Calorific Formula. 

Dulong and Petit and subsequently Favre and Silbermann 
determined the calorific capacity or heat of combustion of 
many substances with more or less accuracy. Dulong endea- 
voured to find a formula for calculating the heat of combustion 
of any fuel of which the chemical composition was known. 



100 LIQUID FUEL AND ITS APPAEATUS 

The capacity given by him to carbon was 7,295 calories. The 
latest determination of Berthelot is 8,137 and that for hyd- 
rogen is 34,500. 

Dulong's formula for fuel according to its composition is, 
with the correction to modern coefficients — 

Cal. =8,137 C + 34,500 (H— £) where 

C is the carbon in 1 kilogram of fuel, and H and O are the 
hydrogen and oxygen respectively, it being assumed that the 
oxygen is already combined with hydrogen and that so much 
of the hydrogen is already useless. Any error would appear 
to be on the safe side, and the formula assumes the return of 
all the gases to 0°C. 

In actual practice, the gases pass at a temperature of over 
100°C, and the water is in the form of vapour, and the calorific 
capacity of hydrogen is often taken as only 29,150 B.Th.U., to 
allow for the heat absorbed in vaporization of the water. 

In Germany, Dulong's formula is thus used in the form — 

Cal. = 8,100 C + 29,000 (H-f) + 2,500S-600W, 

where S is the sulphur present, and W is the weight of hygro- 
scopic water. 

Seeing that in coal the hydrogen is as solid apparently as the 
carbon, it appears correct to take something off the co-efficient 
of hydrogen to allow for the heat absorbed in gasifying it, and 
in the above formula the subtraction of 150 calories perhaps 
helps to make this formula coincide very closely with calori- 
metric results. 

Possibly also the rounding off of the co-efficient for carbon 
from 8,137 to 8,100 helps to correct for the vaporization of the 
carbon compounds which are exothermic when first formed, 
and do not give up the full heat value of their separate hydrogen 
and carbon. Both marsh gas, CH 4 , and ethane, C 2 H 6 , give 
out heat when formed and require it again when dissociated, 
and coal is so complex a body, as are also liquid fuels, that very 
little positive knowledge can be assumed : it is sufficient to 
know that the formula last given is a very fair approximation 
to the truth. 

The Calculation of Temperatures. 

The temperature of combustion of any substances depends 
upon the calorific capacity of the burning material, the total 
weights of the products formed, and the specific heat of the 
products. The calculation of the theoretical temperature is 
therefore simple. 



CALORIFIC AND OTHER UNITS 101 

The specific heat of all bodies, and particularly of gases, 
increases with temperature, and this reduces the temperature 
actually obtained. Though hydrogen has so high a calorific 
capacity, it does not produce a specially high temperature as 
compared with carbon, for in the first place it demands 8 times 
its own weight of oxygen, and secondly the specific heat of the 
product, steam gas, is also high, viz., 0479. 

The calculation of temperature for hydrogen burned with 
oxygen is — 

2Q 1 W 
T = 9 x 0479 = 6 ' 762 °°' = 12 > 202 ° F - 

These are temperatures very much in excess of anything 
secured in the laboratory, which has not reached 3,000°C. 
(even under a pressure of 10 atmospheres). 

With air, however, the oxygen is accompanied by a weight 
of nitrogen 3-32 times its own weight, and to burn 1 unit of 
hydrogen requires 8 pounds of oxygen and 26-56 of nitrogen, 
the specific heat of which is 0-244. The calculation for tem- 
perature is thus — 

T = (9 x 0479) + 2 (26 5 5 6 x 0-244) = 2 > 513 ° C - = ^^ 

The calculation for carbon turned to carbonic oxide is similarly 
derived from the heat capacity =2,453 cal. The oxygen 
necessary is l\ times the weight of the carbon consumed, and 
as the calorific effect of the first oxidation of carbon is 2,453 
calories per kilogram, we obtain — 

T= 2.333 2 x 53 0-24 5 - 4 ' 292 ° C - =7 ' 757 ° F - 

when burned with oxygen, the total product being 2-33 k. of 
carbonic oxide of 0-245 sp. heat. Then, with air containing 
3-32 times as much nitrogen as oxygen, we have — 

T— 2 ' 453 _ 1 485°n 

(2-333 x 0-245) + (1-333 X 3-32 x 0-244) 
= 2,705°F. 
Where the amount of air is in excess of the chemical minimum, 
a further term must be inserted in the denominator ; as neither 
the nitrogen nor the oxygen of the excess air is altered, they 
may be considered together. The sp. heat of air is 0-237, and 
the weight per unit of fuel being W, we have the new term 
in the denominator (W X 0-237), and the temperature of the 
final product is reduced simply because of the greater weight 
of final gases over which the heat generated per unit of fuel is 



102 LIQUID FUEL AND ITS APPARATUS 

distributed. In Table V are given the calorific capacities 
of the various forms of carbon and of hydrogen, together with 
the resulting temperatures of combustion with a minimum 
of oxygen or equivalent air. The values are given per gram, 
litre, pound and cubic foot for combustion to carbonic oxide 
= CO and to carbonic acid = C0 2 for carbon, and to water 
(vapour) and water (liquid) for hydrogen. 

These temperatures are not attained in practice. St. Clair 
Deville considers that they are prevented from occurring by 
the dissociation which is said to occur at high temperatures. 
A certain temperature is attained and further combustion 
ceases until some of the heat has been dispersed, when further 
combustion proceeds. Berthelot, while not ignoring dis- 
sociation, is rather of the opinion that the inability to attain 
theoretical temperature arises from the proved increase of the 
specific heat of all bodies, and especially of gases at high tem- 
peratures. Probably both causes have effect. 

With liquid fuels, which contain so much hydrogen, the 
calorific capacity of the hydrogen cannot exceed 29,100 cals. 
or 52,290 B.Th.U., because the aqueous vapour always passes 
away as vapour. 

One pound of water vapour contains — 

1,091-7 + 0-305 (T - 32°) B.Th.U., where T is the temperature 

Fahrenheit. 

Similarly where T is the temperature Centigrade 1 kilogram 
contains 606-5 + 0-305 T° calories, whence can be calculated 
the heat lost where saturated steam is thrown away. But in a 
furnace the waste gases are much above saturation temperature, 
and all vapour above 212°F. must be calculated to absorb at 
least 0-480 of a thermal unit or calorie per pound or per kilo- 
gram for each degree Fahrenheit or Centigrade beyond 212°F. 
or 100°C. respectively. 

In calculating furnace temperatures there must always be 
added the temperature of the atmosphere to the calculated 
temperature, which is based on the datum of 0°C. The usual 
atmospheric temperature is 15°C. = 60°F. for convenience, a 
sufficient approximation. The total amount of water to be 
allowed for in any fuel sample is nine times the weight of 
hydrogen in the sample plus all the water. Water should be 
nil with liquid fuel warmed sufficiently to cause the water to 
separate. 

In calculations of the hydrocarbon gases the figures given 
above are combined ; thus for benzene, C 6 H 6 , the calorific 
capacity is 10,052 from the gas or 9,960 cal. from the liquid. 



CALORIFIC AND OTHER UNITS 103 

This substance requires in all 3-077 times its weight of oxygen, 
and produces 3-385 parts of C0 2 and 0-6923 of H 2 0, or 4077 in 
aU. 

The calculation for temperature is therefore — 

9 960 
(0^923 X 0-479) '+(3-385 x 0-217) = 9 > 343 ° C - = !M49°F. 

when burned in oxygen. 

With air there is an added weight of nitrogen equal to 3-077 
X 3-32, the specific heat of which is 0-244. 

This product, 3-077 x 3-32 x 0-244 is added in the denomi- 
nator, and the resulting temperature is found to be 2,798°C. 
=r5,040°F. 

Any excess of air above that chemically necessary is then 
allowed for by means of the extra term in the denominator 
(W X 0-237), as above explained. 

Relative Volume of Gases produced by Combustion. 

When a fuel contains carbon only the volume of the gases 
produced by perfect combustion is identical with the air ad- 
mitted to the furnace, for in producing carbon dioxide two 
volumes of oxygen produce two volumes of carbonic acid, or 
C x 2 = C0 2 , which, like almost all compound gas, occupies 
two volumes. 

When combustion is imperfect and carbonic oxide is formed, 
the result is C + O = CO, or two volumes from only one 
volume of oxygen, and the waste gases exceed the volume of 
air supplied. 

Sulphur in a fuel leads to no change in volume. Hydrogen, 
2 volumes, forms with 1 volume of oxygen 2 volumes of gas, 
or H 2 + O — H 2 0=2 volumes of water vapour. But when flue 
gases are collected the water vapour condenses and there is a 
diminution of volume. 

Each unit of hydrogen in fuel requires 8 units of oxygen. 

Expressed metrically, 1 gram of hydrogen will consume 8 
grams of oxygen. As oxygen weights 1-43 grams per litre, 
each 1 gram of hydrogen will cause to disappear 5-6 litres of 
oxygen or nearly 0-2 cubic feet. 

This volume disappears and the total volume of gases must 
be increased by the addition of the volume of oxygen destroyed 
by hydrogen. 

Though not of much account in respect of coal, the large 
percentage of hydrogen in liquid fuel renders the waste gases, 
when cooled, very much less in volume than the original volume 
of air. Thus an ordinary oil may contain 12 per cent, of 



104 LIQUID FUEL AND ITS APPARATUS 

hydrogen, or 120 grams per kilogram. This will destroy 960 
grams of oxygen or 672 litres for each kilogram of liquid fuel. 
In calculating the percentages of the total gases this volume 
of vapour must be allowed for. Per pound of fuel containing 
say 12 J per cent, of hydrogen exactly one pound of oxygen 
will be used measuring 11-2 cubic feet. Thus should the 
apparent volume of air be 260 cubic feet, the actual volume 
would be 271-2. 

The Table of gases (V) will be useful in such calculations. 

Evaporative Power of Fuel. 

The evaporative power of fuel is usually stated in terms of 
the water evaporated from and at, 100°C.=212°F., at which 
temperature all the added heat becomes latent and disappears 
at the rate of 537 calories per kilogram of water, or 966*7 
B.Th.U. per pound. The theoretical duty is thus obtained 
by dividing the calorific power of the fuel by these numbers — 

29 150 
Hydrogen should evaporate ' = 54*28 times its weight 

Do i 

of water. Carbon should evaporate ' = 15*15 times, and 

the best coals have a capacity of about 15 J times, the highest 
values corresponding with the highest proportion of hydrogen 
when this is not neutralized by being already in combination 
with oxygen. Liquid fuel may run as high as 22 evaporation. 

The actual evaporation secured will fall short of the theoreti- 
cal by 15 per cent, in the very best exceptional cases to 30 per 
cent, in good but heavily worked boilers, the results obtained 
depending upon the perfection of combustion, the avoidance 
of excessive air and the proportions and condition of the boiler. 
A good result with coal is 10 J, which corresponds with about 
15 for good liquid fuel. Coal often falls as low as 8 and liquid 
fuel as low as 12. 

Reference is made elsewhere to the supposed superior effici- 
ency of liquid fuel as compared with solid fuel, in regard to the 
fact that Nature has supplied the latent heat of liquidity, but 
it is also shown that probably the effect is small, the latent 
heat of liquidity being only a fraction of that of vaporization. 
Gaseous fuels, therefore, should be expected to give higher 
values than liquid fuels. The formulae for calculating the 
calorific effect of a fuel give a result greater than the actual 
calorimetric values of hydrogen and carbon. In a liquid fuel 
the carbon should give more than its nominal solid rating, but, 
on the other hand, the rating of hydrogen at 29,150 cals. is 



CALORIFIC AND OTHER UNITS 105 

obtained from hydrogen gas, and, in a liquid fuel, the hydrogen 
has been deprived of its latent heat of gasification, and by 
so much must lose effect when burned, and, per pound, the 
hydrogen loses much more than is gained per pound of carbon. 
Solid fuels, of course, lose still more, but the difference between 
liquid and solid fuels is not very great in respect of their differ- 
ence of physical condition. Where liquid fuel secures its high 
calorific value is in its very high percentage of hydrogen, and 
its freedom from oxygen and ash. The absence of oxygen is 
a proof of the full efficiency of the hydrogen, except so far, 
of course, that the hydrogen is combined with the carbon and 
the combination when effected was exothermic. 

As a sample of liquid fuel calculation, a petroleum may be 
taken, such as a heavy Baku oil, with 87*0 per cent, of carbon 
and 13 per cent, of hydrogen. The excess of air will be assumed 
to be 50 per cent, beyond theoretical requirements. The oil 
was tested to give 10,843 calories by Mahler. 

Calculated by the improved Dulong formula we have— - 

Cal. = (8,100 X 0-87) + (29,000 x 0-13) == 10,817 cal. 

which corresponds very closely with the calorimetric test. 

Had the full values of 8,137 and 29,150 been employed, the 
result would have been slightly above the actual finding, and 
for a very pure hydrocarbon it is probable that calculation and 
tests will not prove to be far apart. 

The temperature secured by this oil with the 50 per cent, 
air excess will be — 

10,817 

(•87 X 3-66 X 0-217) + (-13x9 X 0-479) + (3*36 X 332 

x 0-244) + (5-575x0-237). 

In the formula the first term of the denominator gives the 
heat absorbed by the C0 2 formed from 0*87 of carbon, and the 
oxygen consumed is 0-87=2-66 = 2-32. The second term 
gives the heat absorbed by the steam produced from 0*13 of 
hydrogen, and the oxygen consumed is 0-13 = 8 x 1*04. The 
third term gives the heat in the nitrogen which accompanies 
the consumed 3- 36 of oxygen. 

The total weight of air used is thus 3-36 + (3-36 X 3*32) 
=11-15. Then 50 per cent, of this, or 5*575, is put into the 
fourth term with the specific heat co-efficient of air. Working 
out, the result is — 

i^=2,042°C.=3 ( 708°F., 

as the theoretical temperature of the fuel when supplied with 



106 LIQUID FUEL AND ITS APPARATUS 

50 per cent, excess of air. This shows how temperature is 
reduced by excessive air. Granted that this temperature is 
more than would actually be attained owing to the rise of the 
specific heat of gases with the temperature, the fact remains 
that the furnace temperature would be more nearly maintained 
along the flues. The absorption of heat by the boiler, lowering 
the temperature, would set free the heat which has become 
latent under the term specific heat, and the curve of tempera- 
ture drop would be less steep. 

But beyond all this there is a final chimney temperature 
beyond which it is not commercially practicable to reduce the 
gases, and if by using too much air we double the weight of 
rejected gases, these, at a given temperature, will carry off 
just twice as much heat as would be carried off by half the 
weight. Thus, if the chimney temperature is 950°F. or 400° 
above the atmospheric temperature, each pound of gas t runs 
away with approximately 400 X 0*237 B.Th.U.=:94*8 B.Th.U., 
which is about 1,560 B.Th.U. per pound of carbon fuel burned 
or approximately 9 per cent, of the heat, on the assumption' 
that the chemical minimum of air has been used. But had the 
air supply been doubled the heat thrown away would have 
been doubled also, and a loss of about 18 per cent, would have 
been incurred. 

Excepting that it is important to have clear ideas upon the 
effect of air supply, it does not much concern the engineer 
to know what theoretical temperatures are secured, though he 
must be on his guard against unduly low temperatures in the 
furnace, and be prepared to guard against this by proper design, 
such as keeping heat-absorbing surface away from the gases 
until combustion is sufficiently perfect to enable this to be done. 

The engineer is usually concerned with the evaporative 
efficiency of a fuel, and calculates this from and at the boiling 
point of 100°C. = 212°F. The heat of evaporation of a kilo- 
gram of water is 536*5 cals. or 965*7 B.Th.U. per pound. The 
evaporative power of a fuel is therefore to be directly obtained 
by dividing its unit calorific capacity by the heat of vaporiza- 
tion of water from and at 100°C. 

For pure carbon the figure obtained is — 

E — ~ — = 15*165, or, in British figures, 
536*5 

*=w =■»«■ 

the slight discrepancy being due to errors in the equivalents 
for want of unimportant decimals. 



CALORIFIC AND OTHER UNITS 107 

The actual evaporation of a steam boiler never approaches 
the calculated figure within 20 per cent. This 20 per cent, of 
loss of effect is due to several causes — 

(1) The whole of the fuel is not burned perfectly. 

(2) The waste gases are sent away to the chimney at a 

temperature considerably above that of the atmo- 
sphere at which the fuel and air is supplied. 

(3) There is a large excess of air in the waste gases. 

(4) Much heat is lost by radiation from the boiler and 

brickwork; and, with solid fuels, in ashes and 
clinkers. 

M. Clavenad has a peculiar method of calculating calorific 
capacities. He points out that the figures of 8,000 and 34,500 
for the solid and gaseous states of carbon and hydrogen re- 
spectively are incorrect for liquid hydrocarbons. The heat 
disengaged by gaseous carbon when burned is equal to that 
disengaged by four atoms of hydrogen gas. 

The atomic weight of carbon being 12, and one kilogram of 
hydrogen having a power of 34,500 calories, then 1 kilo of 
carbon in a gaseous hydrocarbon will possess — 

34,500 x 4 " 

z-^r— — = 11,500 calories. 

In the complete combustion of carbon the first reaction, 
C + = CO, produces as much heat as the second, CO + O = 
C0 2 . The weight of carbon in one kilo of CO being 0*428 kilo, 
and the combustion of this from CO to C0 2 producing 2,431 
calories, therefore 1 kilo of carbon completely burned must 
produce — 

2 431 v 2 
': * * = 11,360 calories. 
U-4.40 

Hence M. Clavenad takes the calorific power of gaseous 
hydrocarbon as 11,500 or 11,360 for the carbon, and 34,500 
for the hydrogen, figures which, however, will not fit with 
actual determination, because of the disturbing effects of 
exothermism, as in the case of marsh gas, CH 4 , which falls 
much short of calculation. 

Mahler has shown in the table below that the calculated 
calorific capacity on the assumption of H = 34,511 and C = 
7,860 is greater than experiment shows to be the case. 

The difference P — p is less for crude oil than for products 
industrially produced. The calorific power of the various oils 
studied ranges from 10,300 calories for crude Russian to 11,100 
for American crude. 



108 LIQUID FUEL AND ITS APPARATUS 

According to Colomer and Lordier, the relative weights of 
different fuels to give equal evaporation are — 

Petroleum residue 100 

Peat V 320 

Coke 142 

Good coal briquettes 140 

Anthracite (Donetz) 139 

Coal 153 

Moscow Basin 276 

Ural Basin . . 176 

Kauban Basin 140 

Poland . . . : 165 

Silesia 167 

English 139 

Goutal's formula for calculating the calorific value of fuel 
from its composition is — 

P = 82 C + aV ; where 

P — calorific power in calories. 

C = percentage of fixed carbon. 

V = percentage of volatile matter. 

a = a variable co-efficient depending on the amount of 
ash and water in the fuel. 

Using the formula — 

_ V x 100 

x ~~ c + v 

the following values are obtained for (a). 

V'= 5, 10 5 15, 20, 25, 30, 35, 38, 40. 

a = 145, 130, 117, 109, 103, 98, 94, 85, 80. 
This formula is applicable to solid fuels. 



Smoke and Combustion. 
The Combustion of Hydrocarbons. 

When hydrocarbon fuels are burned there may be formed 
smoke of two distinct varieties. The first is the greenish- 
yellow fume which is driven off coal when placed upon a fire. 
This fume is simply hydrocarbon gas with its contained tars, 
and can be burned. It is the usual smoke produced by the 
domestic fireplace, and burns freely when an under fire be- 
comes hot and the gases are once fairly alight. 

The other variety of smoke is the black smoke which deposits 
soot. Soot is a flocculent variety of carbon which is produced 
by the sudden cooling of heated hydrocarbon gases. In the 
furnace of a boiler wherein the green gases are well ignited 
they are allowed to come into contact with the cold surfaces 



CALORIFIC AND OTHER UNITS 



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110 LIQUID FUEL AND ITS APPARATUS 

of the boiler, and soot is formed. Had the green gases been 
supplied with air intimately mixed, they would have burned 
completely with no smoke, if they were not cooled down by 
the boiler. When a boiler furnace is of correct form, the 
combustion of the hydrocarbon gases can be secured when a 
proper admixture of air is carried out, and in the Lancashire, 
Cornish, and other shell boilers, smokeless combustion can be 
approximated if the draught is good. The means of admitting 
air is usually a grid in the furnace door. The air thus admitted 
sweeps over the whole surface of the fire and becomes blended 
with the gases given off the green coal, and perfect combustion 
will take place if there is sufficient free space beyond the bridge 
in which flame can burn unhindered by cold water pipes. 

If, however, the draught is poor, the air drawn in over the 
fire through the door will be insufficient, and smoke will be 
produced. About 3 to 4 square inches of air openings are neces- 
sary for each square foot of grate surface. 

When insufficient draught is due to the smallness of the 
chimney or flues, or to bad brickwork, it can be remedied by 
repairs, or by the use of a small steam jet, to induce a flow of 
air through the door grid. 

If the poor draught is due to the necessity of closing the 
dampers to moderate the intensity of the fires, it is then neces- 
sary to reduce the area of the fire-grate, so that the chimney 
draught may be made more intense on the smaller area, the 
damper being kept open. This keeps up the draught suffi- 
ciently to compel the air to flow in at the door grids in ample 
volume. The same effect may sometimes be secured by fitting 
dampers to the ash-pit opening, so as to control the intensity 
of the fires even with a full open chimney damper. The full 
draught power then remains available to draw in air through 
the door grids to burn the hydrocarbon gases above the fire. 
Any draught less than J-inch water-gauge, or say a velocity of 
30 feet per second, will usually make it impossible to burn coal 
without smoke. 

In no case can smoke be prevented where the gases rise verti- 
cally from the fire and pass directly between the tubes of a 
water-tube boiler, for the necessary mixture of air has not been 
secured. Belleville tried to effect a mixture by blowing high- 
pressure air jets into the furnace in order to mix up the gases, 
but the method is faulty, and cannot be a success where the 
tubes are so close above. The same principles apply to the 
combustion of liquid fuel, with certain differences due to the 
method of firing. With liquid fuel the supply of gas is uniform 
and continuous, and the fuel is supplied in exceedingly small 



CALORIFIC AND OTHER UNITS 111 

particles intimately mixed with air to begin with, and supplied 
with a further volume of air from below. A uniform high 
temperature is maintained in the locus of combustion by a 
sufficient mass of fire-brick work in the form of arches or chequer 
work. 

The production of soot is well illustrated by the system of 
manufacture of lamp-black, which is carried on by burning a 
large number of oil lamps in a confined space with an insufficient 
supply of air at a low temperature. Soot is thus formed, not 
alone by cooling heated hydrocarbon gas, but by attempting 
to burn it with an insufficient air supply. 

Oil fuel will produce dense smoke when not supplied with 
sufficient air, but in all the approved methods of combustion 
the requisite air is supplied, and can be regulated very exactly. 
Combustion also takes place at a high temperature, and the 
flame produced is comparatively short, and combustion can be 
completed in a comparatively restricted space, as in the firebox 
of a locomotive, which can be perfectly fired by oil fuel without 
any change from the conditions found necessary with coal. All 
manner of contrivances have been patented for the prevention 
of smoke, but few, if any, have realized the all-important detail 
of temperature, for without sufficient temperature in addition 
to the proper mixture of air in a furnace of correct form, there 
can be no perfect combustion. 

All smoke troubles may be attributed in general terms to the 
too early application of the heat absorbing surfaces of the boiler 
to the yet unconsumed gases. While the foregoing arguments 
apply more particularly to coal, their principles are equally 
applicable to oil. Anthracite coal, which contains no hydro- 
carbons, burns away altogether at the grate surface with an 
intensity of temperature very much in excess of that of any 
bituminous coal. 

The latter must be distilled on the grate, and much heat is 
absorbed in the gasification of the hydrocarbons. The zone 
of combustion is very much extended, the temperature at the 
grate is less, and it is necessary to conserve the heat generated 
on the grate in order to keep hot the hydrocarbon gases, so 
that these also may burn and not be wasted. With liquid fuel 
the gasification is already partially effected, and combustion 
is rendered more perfect by heating the liquid and also heating 
the air by which it is atomized. Thus, if the oil and air be both 
heated to 200°F., the temperature of combustion will be higher 
by about 150°F. than if both oil and air were supplied at the 
ordinary atmospheric temperature. The following extract 
from the Author's paper on the subject of hydrocarbon com- 



112 LIQUID FUEL AND ITS APPARATUS 

bustion in the Electrical Review, of August 30, 1901, may be of in- 
terest in this connexion with the subject of furnace temperatures. 

Furnace Temperatures. 
An argument in favour of the necessity of refractory furnaces 
for bituminous fuel is that only a proportion of the total calorific 
capacity of a bituminous coal is generated on the grate, and 
therefore the fuel which burns on the grate is debited, not only 
with its own combustion, but also with the splitting up of the 
hydrocarbons and other volatiles, and raising them to such 
temperatures as will enable them to burn at a second zone of 
combustion. 

An average of 18 analyses of Newcastle coal gives the follow- 
ing figures — 

Fixed carbon 48-84 per cent. 

Volatile carbon 33-29 „ „ 

Hydrogen 5-31 ,, „ 

Oxygen 5-69 „ „ 

Nitrogen 1-35 „ „ 

Sulphur 11-24 „ „ 

Ash 3-77 „ 

Calorific capacity 15,203 B.Th.U. 

The calorific capacity of amorphous carbon is about 14,647 
B.Th.U. per pound ; therefore the capacity of the 48-84 per 
cent, of fixed carbon in the above samples must be 7,150 B.Th.U. 
As regards the fire upon the grate, these 7,150 heat-units are 
all we have to work with. We have to draw on them for the 
heat which becomes latent in converting the solid coal to the 
gaseous hydrocarbon. A piece of coal is all solid, and except- 
ing the ash, it all becomes gaseous. Subtracting for cinders 
3-77 per cent., there remains 47 per cent, of volatile solid 
matter, which ultimately passes off in a gaseous state. The 
customary allowance of air is about 18 pounds per pound of 
coal. This also must be heated up to the general temperature 
by the heat developed on the grate by the fixed carbon only. 

The theoretical flame temperature of carbon when burned in 
an exact sufficiency of air (i.e. 11 J pounds per pound) is 4,892°F. 
We can readily calculate the net temperature of all the products 
in the usual manner, though the result will be approximate 
only. We may assume 1 pound of coal, and we will add the 
customary 18 pounds of air, so as to produce a final 19 pounds 
of the total furnace products. As the temperature of combus- 
tion of carbon in air is 4,892°F., when using 11-6 times its 
weight in air, the temperature with 18 pounds of air will be 

12 6 

- -- X 4,892 == 3,245°R But with the heat produced by 



CALORIFIC AND OTHER UNITS 113 

48-84 per cent, of the coal, we have to carry the further load of 
volatile fuel and inert ash that is not burned on the grate, 
together with its similar proportion of excess air. The 
temperature of 3,245°F. x -4884 = 1,584°F., and this is the 
maximum temperature of the products of combustion, assum- 
ing that they escape uncooled. This is a maximum figure, 
because whereas the temperature of combustion in air, namely 
4,892°, is that due to a minimum of air, the reduced tempera- 
ture involved by the use of excess of air as above calculated is 
really too great in part proportion as the specific heat of nitro- 
gen is greater than that of carbonic acid ; nitrogen, of course, 
forms by far the greater proportion of the furnace products, 
and it has a specific heat of 0-244, as compared with carbonic 
acid 0-217. Steam also, which is formed on the grate and 
does its share in reducing the temperature, has the high specific 
heat of 0-480, any free hydrogen that may escape has 3-410, 
and the hydrocarbons have also very high specific heats, for 
example, defiant gas, 0-418 ; marsh gas, 0-593. 

It is thus clear that the temperature of the gases as they 
flow to the bridge is quite low, and so far no deduction has 
been suggested for the vaporization of fully half the solid fuel 
into gaseous form. What, in fact, is the effect of the latent heat 
of evaporating carbon, hydrogen, oxygen, from the solid ? for 
this is really what happens when bituminous coal is burned. 

To evaporate carbon requires 5,817 British Thermal Units 
per pound, this being the difference between the calorific capa- 
city of carbon burned to its monoxide, and of this monoxide 
burned to dioxide respectively. Hydrogen and oxygen com- 
bined require 11,000 heat-units per pound of hydrogen to raise 
them from the solid to the gaseous state. 

Let the figure of 7,000* units of latent heat per pound be 
assumed for the whole of the volatile constituents of coal, that 



1 Possibly the figure of 7,000 may be too high, except for the carbon 
and hydrogen compounds. The value of carbon is as above about 
6,000, as evidenced by the difference between the heat produced by 
burning carbon to its first oxide, and then again to its second oxide. 
That for hydrogen must be over 7,300, but the values for oxygen 
and nitrogen are low. Lechatelier determined the molecular specific 
heats of the elements as 6-65 +at, where a is the constant, and t is the 
absolute temperature at which the measurement is taken, a was given 
by him as 0-001 for a considerable number, but he gave values for 
a = 0-008, and there is ample proof in Berthelot's great work that at 
high temperatures the specific heats of some substances may be double 
and treble the customary figure of 6-65. As the distillation of coal 
in a furnace is desired to be effected at at least 1,000° or 1,500°F. (say 
550°C. to 800°C.) the specific heats will be something higher than 6-65. 

H 



114 LIQUID FUEL AND ITS APPARATUS 

is to say, for all that part which does not burn directly on the 
grate. This proportion was found above to be 47 per cent, 
of the whole, so that, per pound of fuel, 3,290 heat-units (-470 
X 7,000) must disappear in evaporating the volatile carbon, 
the oxygen, hydrogen, and other gases which exist in combined 
solid form in coal. 

But we have already found that the total heat generated by 
the 48-84 per cent, of fixed carbon produces 7,150 heat-units. 
The difference between the heat generated by the fixed carbon 
and that absorbed by the volatile hydrocarbons of these parti- 
cular Newcastle coals is thus only 3,870 units. This is all the 
heat that remains available for raising the temperature. 

Now we have found an ultimate temperature of 1,584 when 
not allowing for the latent heat of gasification. We must 
correct this. It is less in the ratio of 3,870 : 7,150, or 857°F. 
That is to say, if bituminous coal be burned on a grate and 
those parts of the coal which volatilize and burn as flame be 
gathered unburned, the temperature of the whole production 
of the furnace, including 18 pounds of air per pound of fuel, 
would only be 857°, or considerably less than that necessary for 
ignition. 

In the first place, this tells us that it is of the first importance 
to diminish the supply of air to a minimum. 

By passing only half the air through the grate and adding 
the remainder as required to the evolved gases at a subsequent 
point, we can at once practically secure double the above tem- 
perature, or say 1,600°, a temperature at which ignition is 
possible. Moreover, even 9 pounds of air is 35 per cent, in 
excess of the allowance necessary to burn the fixed carbon of a 
pound of bituminous coal, so that it would be liberal practice 
to pass only half the total air through the grate. Some of the 
heat developed on the grate is at once radiated to the boiler 
surfaces ; hence my constant contention that furnaces should 
be lined wholly or partially with refractory material in order 
to conserve the necessary temperature. 

It must not, again, be overlooked that some of the evolved 
hydrocarbons do burn on the grate and at the fire surface. In 
fact, they commence to burn at once, and continue to burn to 
the end so long as conditions are maintained favourable to 
continuous combustion. 

Rankine's estimate of air as found in ordinary practice was 
25 pounds per pound of fuel. The so-called chemical minimum 
is 11 J pounds. I have assumed 18 pounds as good practice, 
but as low or lower than 15 pounds has already been recorded 
by Mr. Michael Longridge. 



CALORIFIC AND OTHER UNITS 115 

If, however, we pass 9 pounds of air through the grate and, 
say, a further 6 pounds over the grate, in fine streams, to assist 
the combustion of the hydrocarbons, and take care that we 
do not abstract heat faster than it is generated by the burning 
gases, we ought to be able to secure perfect combustion with 
less than 18 pounds of air per pound of coal. There is no 
known reason why we should not. The impossibility of smoke- 
less combustion has been widely and hniuentially urged, but 
never so much as by those engineers who cram their heating 
surfaces right upon the fire and never trouble their brains to 
inquire why it is that a thermometer shows the same continu- 
ous reading of 32 C F. in a vessel of melting ice with a flame 
under it until all the ice is melted. A piece of coal, like a 
piece of ice, is simply so much solidified gas, and absorbs 
heat greedily while vaporizing, but it cannot be burned like so 
much solid carbon, but must have length and space in which 
to mix and combine with the oxygen of the air. 

The following figures, based on Berthelot's investigations, 
will be useful in this connexion, for they show the enormous 
differences which exist between matter in its several states. 
Carbon, existing as it does free in Nature in at least three solid 
alio tropic modifications, is a peculiarly interesting example. 
We do not know it as a liquid or as a gas except in combi- 
nation. Its three solid forms of crystalline, graphitic, and amor- 
phous, show by their variations of " latent " heat how great 
is the effect of form, even when the various forms affect one 
state alone. The gaseous state of carbon and the heat neces- 
sary to put it into that state are easily argued from the difference 
of heat disengagement in the two oxidations. As the table 
shows, the oxidation of 1 pound of carbon (diamond) produces 
3,915 British thermal units when the product is monoxide. 
The heat disengaged by complete oxidation is 14,146 units. 
The difference of 10,231 — 3,915 =6,316 units, and this is 
obviously the minimum heat of vaporization of the diamond. 
Similarly, for the amorphous forms of carbon, the first oxida- 
tion produces 4,415 units, and the complete oxidation produces 
14,647. Here the same difference is 5,817, and the greater 
heat evolution represents the energy necessary to recrystallize 
the diamond. Thus we learn that when the diamond crystal- 
lized it evolved heat, and we learn that the difference between 
graphite and the diamond is less than between graphite and 
amorphous carbon. In fact graphite is about six-sevenths 
along the road to becoming diamond. 



116 LIQUID FUEL AND ITS APPARATUS 

Heat generated by the Combustion of 1 pound of Carbon. 



State of Carbon. 



Diamond. 

Graphite .... 
Amorphous . 

,, ... 

Gaseous .... 

,, .... 

21 carbon monoxide 



Product of Combustion. 



Carbon monoxide 
dioxide 



monoxide 
dioxide 
monoxide 
dioxide 



British Thermal Units 
per pound. 



3,915 
14,146 
14,222 

4,415 
14,647 
10,232 
20,463 
10,231 



Metamorphic Conversions. 



Carbon (diamond) . 
(graphite) . 
(amorphous) 
(diamond) . 
(diamond) . 
(graphite) . 



Gas 



Carbon (amorphous) 
(graphite) . 
., (amorphous) 



Heat absorbed. 



6,316 
6,241 

5,817 
499 

74-7 
424 



Stated briefly, about half the weight of a bituminous fuel 
burns upon the grate itself, and produces half the total heat of 
combustion ; but that owing to the heat of formation of 
gaseous hydrocarbons, and generally to the vaporization of 
solid fuel, which absorbs so much heat, only about one-fourth 
of the total heat of combustion is sent off from the grate as 
sensible heat. The remaining three-fourths are developed 
between the fire surface and the extreme range of combustion. 
This range varies, of course, with the short or long flaming 
quality of the coal. Anthracite coal, which is entirely of solid 
carbon, and is therefore almost wholly burned upon the grate, 
will produce a temperature at the surface of the grate very 
considerably higher than bituminous coal will produce con- 
tinuously. This is the reason why so much trouble is experienced 
with the grate bars when anthracite is used. It is evident that 
every fresh charge of bituminous coal has a very chilling effect 
upon the fire, and this is especially the case with intermittent 
firing. The chilling effect of a fresh charge of anthracite is 
merely that due to the heating of solid fuel, and is compara- 
tively trivial. The bad effect of anthracite coal upon grate 
bars is usually attributed to some specially bad quality in the 
coal itself ; but this is probably erroneous, the real cause being 
simply the high temperature, which melts the cast-iron bar. 
This explanation receives confirmation in the fact that bars go 
very quickly when they stand above the general surface of the 



CALORIFIC AND OTHER UNITS 117 

grate, projecting their upper edge into the body of the fire. 

The question of combustion is further complicated by the 
variation of the specific heat of gases at high temperatures. 

The subject has been most thoroughly investigated by M. 
Berthelot, to whose great work, Thermochimie, it is hardly 
necessary to say the Author is much indebted. That the specific 
heat of gases does increase with temperature there is now no 
doubt. At ordinary furnace temperatures the effect is not 
great, but such as it is, is in the direction of keeping down 
temperatures below what they would appear to be when calcu- 
lated on the basis of constant specific heat at all temperatures. 

First, only half the coal is burned actually on the grate ; 
secondly, the other half and the excess of air work ever to 
reduce the temperature ; thirdly, there is the reducing effect of 
vaporizing half the fuel, and this is simply enormous, and has 
never before been recognized as considerable, if indeed it has 
even been allowed to suggest itself ; fourthly, there are the 
very active heat-absorbing surroundings of water-cooled plates 
or pipes. All these causes work together, with the further 
assistance of the increment of specific heat, to reduce the pro- 
ducts of bituminous coal to a temperature below that at which 
perfect combustion is possible. The combined action is so 
powerful that even so-called smokeless Welsh coal will smoke 
in boilers of the Belleville type. 

In any case, even if the effect of vaporizing the solid fuel 
has been over-estimated, the fact remains that it nearly ap- 
proaches the figures given, and must prejudicially affect the 
furnace temperature. It teaches us at once the complication 
involved in burning bituminous coal, and the hopelessness of 
those forms of furnace that attempt to extract heat from the 
fire within a short distance of the fire itself, and this is equally- 
applicable to liquid fuels which indeed are so very offensive 
if badly burned that they usually are furnished with brick 
linings for heat conservation and are burned without smoke. 



Flame Length. 

The length of flame from a burning hydrocarbon is largely 
determined by the intensity of the combustion, as well as by 
the perfection of the air admixture. A well mixed gas burning 
at a high temperature will produce a short flame, whereas the 
same gas burned in water-cooled boiler flues will produce exceed- 
ingly long flames. By using suitable furnaces with refractory 
linings, combustion may be made to complete itself in a short 



118 LIQUID FUEL AND ITS APPARATUS 

distance. It does not follow because a certain fuel produces a 
flame 60 or 80 feet in length that it will be necessary to line 
the combustion space to a distance of 60 or 80 feet. 

The very fact of lining it for one-tenth that length might so 
promote rapid combustion as to shorten the flame to even less 
than one-tenth. Once, however, that the initial temperature 
is reduced below a certain figure, the length of flame cannot be 
kept within bounds. This is important to remember, for even a 
hot flame will be extinguished after it has encountered the cold 
tubes of a water tube boiler. In comparing water tube and 
cylinder boilers, it should be noted that the area of cold surfaces 
over the fire of a cylinder boiler, either internally or externally 
fired, is a very small proportion of the whole heating surface. 
In the ordinary form of water tube boiler, where the gases rise 
directly between the water tubes, the proportion of cold surface 
at once encountered by them is very great. Apart from the 
errors already pointed out, the vertical rise of the gases from 
the fire is bad practice. 

The water tube boiler need not of necessity be thus badly 
arranged. It can be set to give the most perfect combustion. 
Perfect combustion only takes place at a high temperature. 

Flame Analysis, 

The vibration velocity of light, by which is meant those 
etheric waves which are capable of making their existence felt 
to our organs of vision, varies from four hundred billion oscil- 
lations per second to nearly eight hundred billions ; that is to 
say, about one octave alone comes within the capacity of the 
eye to discern. The lower number corresponds with the extreme 
red of the spectrum, the higher frequency with the extreme 
violet. Beyond the extreme red is a long range of oscillations 
- — rays invisible to the eye — which manifest themselves as 
heat. Beyond the extreme violet rays exist a long series of 
invisible rays known as actinic or chemical rays. These are the 
rays which are most energetic in producing chemical effects. 
They are the active rays in photography, and are those which 
produce sunburn and the like effect from exposure to electric 
light. As these ultra-violet rays produce chemical effects, so 
are they produced by chemical action. The more intense the 
act of chemical combination, as in the burning of carbon, the 
greater will be the actinism of the fight produced. Very high 
temperatures produced by combustion approach a white 
colour the more closely as the temperature rises, and to some 
eyes — fatigued by too much observation of molten cast-iron — 



CALORIFIC AND OTHER UNITS 119 

the clearance of the final hot slag gives a peculiar neutral light 
lavender colour indicative of the high temperature of a common 
foundry cupola. 

The proportion of rays of any particular colour in a furnace 
will indicate the intensity of the action which is going on with- 
in that furnace. It is extremely difficult for the most highly 
experienced eye to discern the full action of a furnace at high 
temperature — not perhaps so much because of inability to 
estimate the relative amounts of colour present as because of 
the superabundance of heat rays which accompany the chemical 
rays, and generally the dazzling effect of even moderate tem- 
peratures. 

The extreme brightness of the steel furnace has necessitated 
the use of blue or violet coloured glass to enable the workmen 
to watch the progress of the melt without discomfort. 

Engineers have not accepted as they ought to accept the 
teachings of physics as an aid to correct practice. Science and 
practice have been kept apart. In the combustion of fuels, 
this neglect of scientific teaching is almost universal. The 
combustion of fuel, especially of bituminous coal, is carried 
out along extremely unscientific lines. The assertion is some- 
times made that the hydrogen of bituminous coals cannot 
be counted upon as useful calorific ally. This conclusion is 
erroneous. 

Hydrogen ignites so very much more readily than carbon, and 
at so low a temperature, that the probability is the hydrogens 
do burn, and in doing so they snatch the available oxygen 
from the surrounding air and deprive the nascent carbon of 
any opportunity of combustion, causing it to deposit as soot. 
Unless there is sufficient temperature there is no hope of burn- 
ing bituminous coal or oil, as it very easily can be burned, 
without the formation of smoke. Temperature is so closely 
connected with actinism that the analytical investigation of 
the light of a furnace will give a fair insight into its conditions 
of temperature. By means of transparent media of suitable 
composition fight may be analysed in a manner that will afford 
great assistance in arriving at sound engineering conclusions 
and practice. Such media are coloured glasses. A ruby- 
coloured glass will cut off all rays of fight of higher vibration 
than ruby colour. Only the lower end of the spectrum will 
be visible through such a glass. On the other hand, by means 
of a violet-coloured glass, all the less active rays than violet 
will be eliminated, and the most brilliant of furnaces may be 
thereby rendered easily visible, its interior being coloured the 
peculiar lavender grey colour, or approaching this tint, which 



120 LIQUID FUEL AND ITS APPARATUS 

marks the ultra-violet end of the spectrum. The more perfect 
the combustion, the larger will be the proportion of violet 
light emitted by the flames. 

In a well-designed furnace, the whole internal surface of 
which is brilliantly incandescent, light proceeds from every 
portion of the area and from the flame itself. There are no 
non-luminous areas. Occasionally in the mass of flame dark 
streaks may be seen. These represent streams of burning 
gas, which, while incandescent, are below the violet stage. 
They may be traced to a point of disappearance, and they 
would probably radiate some light if the colour of the glass 
were less violet and more blue. 

Let the observation now be transferred to a less perfect 
furnace, such as that of the common setting of the water tube 
boiler, where the flames rise vertically among the tubes from 
the grate surface, and good combustion is impossible. With 
the unprotected eye the flames will appear to be giving light 
all the way from the fire surface to between the tubes. Com- 
bustion appears fair. If, however, these light-giving flames 
be examined by the aid of violet glass, they will be cut down to 
short tongues of flame projecting but little above the fire sur- 
face. Even these tongues of flame give forth little illumination. 
Above the flames the gases appear to be simply dark-coloured 
streams of gas, soofc laden and murky. The violet glass or 
analyser has cut out all the rays of small actinic power and 
small temperature, with the result that the only remaining 
light rays are those immediately above the furnace. 

The effect of radiation is to cool the flames below the range 
of violet long before they have risen to the level of the tubes. 
Apparently there is nothing but radiation to explain the reduc- 
tion of temperature. 

This method of analysis of the products of the fire is useful 
not merely because it enables a furnace interior to be visually 
examined with ease and comfort, but because it shows so 
clearly the effect of a good design and the bad influence of 
premature cooling. It affords most conclusive testimony to 
the benefits that accrue from proper design, and should be an 
effectual silencer of those who argue that smoke is one of the 
unfortunate inevitables of combustion in place of being but a 
proof of ignorant and careless design and neglect of the plainer 
principles of chemical science. 

The use of violet-coloured glass is essential. It is not 
simply that it is requisite to reduce the amount of light which 
meets the eye and renders vision impossible. Such a result 
could be attained by means of glass otherwise coloured, as by 



CALORIFIC AND OTHER UNITS 



121 



smoke, so that it is less transparent, but still not diffusive, as 
is ground glass. 

Violet glass or the higher blue colours are necessary because 




Fig. 7„ Weir Small Tube Boiler, with Refractory Combustion 

Chamber. 

The walls of the furnace are lined with fire-brick slabs, threaded on the inside row of tubes, 
and beyond the furnace chamber is a further combustion chamber also lined with fire-brick. The 
hydrocarbon gases have thus a long distance to travel before they reach any seri:us area of cool 
tube surface ; the furnace is maintained at a high temperature, and there is large space for the 
combustion of the gases in a hot chamber, whereby alone combustion can be secured perfect. This 
boiler can be fixed either from side or ends, and represents the latest and most improved practice 
in water tube boilers, recognizing the principles essential to perfect combustion. The hot gases 
travel along the length of the tubes, completely enveloping them. The outer casing is of fire brick 
slab with an outer sheet of steel. The following shows result of tests of two of these boilers 
with coal — 

SiDgle-ended. Double-ended. 

Grate surface 48-75 48-75 53 53 

111 1 

Ratio to heating surface — — 

45 45 41-3 41-3 

Funnel draught 3-21 forced 0-6 nat. 3-5 forced 0-625 nat. 

Calorific value of coal 13-38 13-38 13-2 13-2 

Coal per square foot per hour 62-2 29 63-4 29-1 

Evaporation per lb. of coal from and at 212° 9-05 lb. 10-7 lb. 8-65 lb. 9-76 lb. 

Ditto per square foot heating surface . . 12-5 lb. 6-918 lb. 13-27 lb. 6-86 lb. 

Boiler efficiency 67-65 80-0 65-5 74 

Tire thickness 12 in. 12 in. 9 in. 9 in. 

Funnel temperature — 789°F. 930°F. 780°F. 

Steam pressure, lb 285 251 275 276 



of their specially analytical properties. I am not prepared to 
say that perfect combustion cannot occur at temperatures 
below those which are associated with the light rays that can 
traverse violet glass. It is, however, very probably true that 



122 



LIQUID FUEL AND ITS APPARATUS 



the violet degree of actinism must be very fully developed if 
combustion is to be perfect, and this degree of actinic effect 
cannot be associated with temperatures that can be secured 
in any furnace so arranged that the gases rise vertically from 
the grate surface to pass between the water pipes before they 
have been thoroughly commingled and burned in a free space. 



















No. 


V 








































No 


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Ight Gray Smota 
No 3. 












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IB j 


























































































































































































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Darker Gray Smoke 



Dark Cray Smoke. 



Fig. 8. Ringelmann's Smoke Chart. No. 

All Black. 



— All White. No. 5 — 



Thus the ordinary arrangement of water-tube boilers is abso- 
lutely hopeless and impossible. A single inspection of such a 
furnace through the analyser will effectually convert any open 
mind, and point the necessity for better practice. 

Mr. Weir, of Glasgow, designed the small tube boiler shown 
in the Fig. 7, with the necessities for combustion before him. 



CALORIFIC AND OTHER UNITS 123 

It will be observed that in this boiler the gases from the coal 
must pass through a large firebrick-lined furnace and com- 
bustion chamber before they reach the tubes. Combustion 
is thu» assured by a sufficient conservation of temperature. 
The principles which underlie perfect combustion are here 
assured, and smokelessness results. The same principles 
applied to liquid fuel are followed by equally happy results. 

But in recent practice with liquid fuel it is found possible 
to attain very good combustion with little or no smoke without 
fire-brick lining to the furnace. See the latest practice of the 
Wallsend Slipway and Engineering Co. 

Ringelmanri 's Smoke Chart. 

This chart (fig. 8) is very useful as a means of comparing 
smoke. The chart should be ruled in squares of about eight 
inches, and hung about 50 feet from the observer, at which 
distance each square assumes a uniform tint all over, the rulings 
being indistinguishable. There are six cards in a set No. 
being all white and No. 5 all black. 
The proportion of the lines is as follows — 

No. 1. Black lines 1 mm. thick, spaces 9 mm. wide 

No. 2. „ „ 2-3 mm. „ „ 7-7 „ „ 

No. 3. „ „ 3-7 „ „ 6-3 „ „ 

No. 4. „ „ 5-5 „ „ 4-5 „ 

The illustrations are reduced from a larger size, and the pro- 
portion of black and white is of course preserved. 

In marine work smoke may be observed by means of windows 
placed in the uptakes. An incandescent lamp on the other 
side of the uptake should be visible through the smoke. It 
should not be perfectly clear, for an entire absence of smoke 
may indicate an excess of air. A slight smoke indicates, when 
conditions generally are good, that air is not greatly in excess. 



Part II 
PRACTICE 



CHAPTER VII 

OIL FUEL AT SEA. 

Oil Storage on Ships. 

OBVIOUSLY the double bottom of a ship now used for 
water ballast is the place in which to carry oil fuel, leaving 
other spaces free. 

As each fuel tank is emptied it can be filled with water. 
Lloyds' Register of Shipping publishes certain rules applicable 
to existing vessels, which should be studied. As they may 
be changed from time to time, they are not given in this book. 
Both Lloyds and the Board of Trade place only necessary 
safeguards, and do not oppose the use of liquid fuel. Sir 
Fortescue Flannery states that the peculiarly penetrative 
qualities of refined petroleum do not attach to the more viscous 
fuel oil, which he avers to be as easy to retain as water by the 
same class and quality of riveted work. 

Additional water-tight subdivision is, however, advised as 
a safeguard against the scend of a half-empty oil tank, but in 
small or medium ships the usual subdivision is thought sufficient. 

In the system of storage adopted on the s.s. Murex, a vessel 
with all her tanks adapted to carry either general cargo or 
refined oil, but not originally planned for using liquid fuel, for 
which purpose she was converted by the Wallsend Slipway 
and Engineering Company, there is no double bottom below the 
cargo tanks, which extend to the skin of the ship, but the bottom 
is double below the engines and boilers, and coffer-dams are 
put in at the fore and aft ends of the cargo space, and, with the 
fore and aft peaks, have been arranged to take the fuel oil. 
Service tanks were placed in the 'tween decks. 

A flange on deck is coupled up to the pipe from the store 
tank, and oil passes by pipes to the various tanks, whence a 
pump lifts it to the service tanks, which are provided with 
overflow pipes, steam heater coils, and water drain pipes. 

All leakage in the power compartment is intercepted by the 
drainage wells, so that the ordinary bilge is kept free. These 
intercepting wells have their own suction and delivery pipes. 

137 



128 LIQUID FUEL AND ITS APPARATUS 

In a regular oil tank steamer on the Flannery-Boyd system, 
the oil to be used is carried in the fore and aft peaks and in 
the ballast tanks under the engines and in the division bulk- 
heads, the cargo of oil being carried in the remainder of the ship. 

Between the oil tanks and the remainder of the ship it is con- 
sidered necessary to place a coffer-dam. In a tank steamer 
the rest of the ship means the engine and boiler compartments. 
This coffer-dam is two transverse stiffened bulkheads extending 
across the ship and properly filled with water as a safeguard 
against leakage of oil. In practice this coffer-dam is often 
filled with fuel oil, a practice upon which doubts may be ex- 
pressed, for apparently this destroys much of the safety in- 
tended to be given. Oil fuel is also carried in the double 
bottom below the engine compartments, which again is a point 
open to discussion, for a vessel might be so injured by going 
aground as to flood the boiler compartment with oil with risk 
of explosion. 

It is safer practice to exclude oil from both the power com- 
partment bottoms and from the coffer-dams, the latter being 
kept perhaps narrower than they are now. 

Where the oil is of a specially heavy class, there might not 
be much risk if it did leak into the firehold, and good residuum 
or astatki would be something of a safeguard between the 
main tanks of crude oil and the boiler room. Be this as it 
may, the presence of a narrow water space outside the oil 
fuel coffer-dam gives a better margin of safety. 

The riveting of oil-tight plating is usually 3 to 3 J diameters 
in pitch. Old ships, to be rendered fit for oil carrying, which 
have rivet spacings of 7 to 8 diameters, may thus have a new 
rivet put into each spacing. Such ships usually require 
additional deck beams, as a rule. Ships should have not less 
than eight water-tight compartments, and the separating 
bulkheads, if oil tanks, ought to be connected directly to the 
skin of the ship, all possible empty spaces being avoided. Oil 
is filled into tanks so as to stand 2 feet above the upper deck 
level in the expansion trunks. The gases driven off from oil 
are heavy, and settle at the bottom of any space into which 
they obtain access. Ventilation is required to get rid of such 
gases. Air should be admitted through cowl heads to the upper 
part of the place to be ventilated and removed from the lower 
part. It will dilute and carry off the accumulated gas. Such 
air outlets should have induction openings to assist the current. 
The general direction of air movement in a ship is from aft 
forward, and advantage may be taken of this in arranging the 
ventilation. 



OIL FUEL AT SEA 129 

Great care is needed to joint all oil pressure pipes carefully. 
The screw threads should be good, and ought to make tight 
joints with only a little smear of litharge and glycerine, or 
Venetian red and shellac. Pipes must not be concealed be- 
neath floor plates, in bilges, or behind casings, but ought to 
be fully exposed to view. 

An oil cargo being so easily mobile with movement of the 
ship, it is necessary that the tanks should be full, so that there 
may be no surging. Hence the use of expansion trunks to 
permit of this, and allow expansion without waste or pressure 
being the result. Surging plates must be employed in those com- 
partments, which may not be always full, as the fuel tanks, and 
no compartment should occupy too much of the length of a ship 
without a bulkhead. Similarly bulkheads are stiffened from 
one to the other by longitudinal plates, which check transverse 
surging, or scending. The ordinary cargo boat, when fitted for 
fuel oil, is re-riveted when necessary, and the oil fuel is carried in 
the double bottom, and can be replaced, as consumed, with 
water ballast. Oil is also carried in the fore and aft peaks. 

Oil Steamers. 

One of the best examples of an oil steamer is the s.s. Trocas, 
which has been fitted for liquid fuel by the Wallsend Slipway 
and Engineering Company, Ltd., the system adopted being 
the Flannery-Boyd with Kusden & Eeles burners. 

The ship is an oil-carrying vessel of 347 feet in length and 
45-7 feet beam, and at full load carries 6,000 tons of oil. 

One of the greater obstacles in the way of fitting old steamers 
with liquid fuel-burning arrangements is the difficulty of con- 
structing suitable spaces to carry the liquid fuel. Ordinary 
coal bunkers are of course not suitable, as the riveting and 
plating is not oil-tight. In the Flannery-Boyd system the 
oil is carried in all the ballast tank spaces throughout the ship, 
namely, the fore and aft peaks, the double bottom ballast tanks 
under the engines and boilers, the forward ballast tank adjacent 
to the fore peak, and the forward and aft coffer-dam. 

The main difficulty in carrying liquid fuel in these spaces 
is that some water always remains in a ballast tank, owing to 
the difficulty of completely draining it. This water becomes 
mixed with the liquid fuel, and passing to the burners causes 
dangerous explosions, and generally puts out flame. It is 
therefore necessary to eliminate the water. To do this two 
settling tanks of large capacity are placed in the 'tween decks 
amidships, adjacent to the boiler room bulkhead. These tanks 



130 LIQUID FUEL AND ITS APPARATUS 

are^fitted with heating coils to enable the liquid fuel to be 
heated to a sufficient temperature to allow of the water freely 
separating. The water then settles to the bottom of the tank, 
and can be drained off. 

Each tank is made of sufficient size to contain half a day's 
supply, so that half a day is allowed for the water to become 
separated. From these separation or service tanks the oil 
gravitates to the burners, and is sprayed by a jet of steam. 

Each furnace is fitted with two burners, and the furnace 
arrangements are such that the complete coal burning gear 
remains intact when burning liquid fuel, so that the system of 
either coal burning or liquid fuel burning can be resorted to at 
will. 

If the vessel is burning liquid fuel, and it is found necessary 
from economical reasons to resort to coal burning, it is only 
necessary to rake a few broken fire-bricks from the bars and 
disconnect the burners and light a coal fire. This operation 
can be carried on without stopping the vessel at sea ; the 
whole operation in a large vessel can be carried out within an 
hour. 

The s.s. Trocas has three large single-ended boilers and one 
donkey boiler. The large boilers have each three furnaces, 
and the small boiler has two furnaces. All are fitted for liquid 
fuel. 

The question of safety and flash-point is of importance. 
The British Admiralty did require a flash-point of 270°E., 
but now accept a minimum of 175°: Lloyds' register, of 200°, 
now reduced to 150°, while the German authorities have 
accepted as safe 150°. Fuel of the lower flash has been in 
constant use for four years in British and Dutch mercantile 
vessels, with complete immunity from accident. It is not 
desirable to fix a flash-point higher than is really necessary for 
safety, because high-flash points are obtained by removing 
the more volatile parts of the liquid, so as to leave a thick 
and sluggish residuum, which requires much power to pulverize 
it. The London County Council ask for 150°. 

Comparative Advantages for War Vessels. 

Sir Fortescue Flannery says : " The problem that confronts 
every designer of a warship is the combination of the maximum 
speed, armament, ammunition supply, protection, and range 
of action in the smallest and least expensive hull, and any 
reduction of weight and space of these is a saving which acts 
and reacts favourably upon the problem. The comparisons 
between coal and oil fuel realized in recent practice are that 



OIL FUEL AT SEA 131 

2 tons weight of oil are equivalent to 3 tons weight of coal, and 
36 cubic feet of oil are equivalent to 67 cubic feet of coal as 
usually stored in ships' bunkers ; that is to say, if the change 
of fuel be effected in an existing war vessel, or applied to any 
design without changing any other of the data than those 
affecting the range of action, the range of action is increased 
50 per cent, upon the bunker weight allotted, and nearly 90 
per cent, upon the bunker space allotted. 

" The coal protection of cruisers, if an advantage — a matter 
of opinion — would disappear with the use of liquid fuel, because 
it would be for the most part stowed below the water line, if 
not wholly in the double bottom. The double bottom and 
other spaces, quite useless except for water stowage, would be 
capable of storing liquid fuel, and the space now occupied by 
coal bunkers would be available for other uses. 

" The ship's complement would be reduced by the almost 
complete abolition of the stoker element and the substitution 
of men of the leading stoker class to attend to the fuel burners 
under the direction of the engineers, and the space of stokers' 
accommodation, their stores and maintenance, would be saved. 
The number of lives at risk and of men to be recruited and 
trained over a long series of years would be reduced, without 
reducing the manoeuvring or offensive or defensive power of 
vessels of any class in the fleet. 

" Re-bunkering at sea — so anxious a problem with coal — 
would be made easy, there being no difficulty in pumping from 
a store ship to a warship in mid-ocean in ordinary weather. 
Three hundred tons an hour is quite a common rate of delivery 
in the discharge of a tank steamer's cargo under ordinary 
conditions of pumping. 

" The many parts of the boiler fronts and stokehold plates, 
now so quickly corroded by the process of damping ashes before 
getting them overboard, would be preserved by the action 
of the oil fuel, and the same remark applies to the bunker 
plating, which now so quickly perishes by corrosion in way of 
the coal storage. 

" Liquid fuel, if burned in suitable furnaces with reasonable 
skill and experience on the part of the men in charge, is smoke- 
less. It is easy to produce smoke with it, but this is evidence 
of its being forced in combustion, or of the detailed arrange- 
ments of the furnace being out of proper proportion to each 
other. In regard to smokelessness, it is, when used under 
conditions customary in the merchant service, not inferior to 
Welsh coal, and superior to any other coal ordinarily in use. 

" The cost of oil in the East is less than the cost of Welsh 



132 LIQUID FUEL AND ITS APPARATUS 

coal when the cost of transport and Suez Canal dues are added 
to the original price of coal as delivered in a Welsh port." 

It is only since Texas oil has been discovered that the success- 
ful competition of oil has appeared probable to the west of the 
Suez Canal. In the mercantile marine advantage is gained 
by a reduction of the stokehold complement, a crew of thirty- 
two being reducible to eight. 

Fast Atlantic liners find it difficult to get coal to their boilers 
for the firemen to burn, and they lose time in consequence, even 
when their engines and boilers are in perfect order. This 
difficulty disappears with oil, and there is a saving of space 
previously occupied by men and stores. 

Allowing 3 tons of coal to be equal to 2 tons of oil, a first-class 
Atlantic liner will gain 1,000 tons for freight, as well as the 
whole of the bunker space. That is, with oil in the peaks 
and ballast tanks, there will be a gain of 100,000 cubic feet of 
paying space, and for most ships at least a fourth of the coal 
bunker space could be used for cargo. There is in addition 
the saving in time when coaling. Oil is pumped in without 
the help of a man. No fires require to be cleaned ; there are 
no ashes to be removed. 

Fires made by oil are perfectly steady, the steam pressure is 
constant, while the temperature of the stokehold in steamships 
is lower, since the furnace doors are never opened and hot 
cinders are not pulled out into the room. 

The loss of heat up the stack is reduced owing to the clean 
condition of the tubes and to the smaller amount of air which 
has to pass through the furnaces for a given calorific capacity 
of fuel, and there is a more equal distribution of heat in the com- 
bustion chamber, as the doors do not have to be opened ; con- 
sequently there is a higher efficiency. The heat is easier on 
the metal walls of the boiler, being better diffused over the 
whole surface. 

The cost of handling fuel, by pumps, is reduced. 

No firing tools or grate bars are used, 1 to damage the furnace 
lining. 

No dust fills the tubes to diminish the heating surface. 

The fire can be regulated from a low to an intense heat in 
a short time. 

Many factories in Pennsylvania and Ohio had to increase 
their boiler capacity by about 35 per cent, when returning to 
the use of coal on account of the high cost of oil. 

1 Grate bars may be employed, under certain conditions, as explained 
elsewhere. 



CHAPTER VIII 

MARINE FURNACE GEAR 

THE use of steam or of air for atomizing is a mixed ques- 
tion. Steam is more convenient, and is naturally first 
used, but it becomes so severe a drain on the fresh water supply 
that it is practically inadmissible at sea. 

The claim that its oxygen is set free by the fire and burned 
with advantage to the evaporative efficiency of the boiler 
cannot be allowed. The dissociation of water or steam absorbs 
exactly as much heat from the fire as is given back by the re- 
combination. 

Some makers of atomizing apparatus claim to secure a softer 
flame with steam, but so far as our chemical and physical 
knowledge extends, air ought to be superior. It requires, 
however, to be first compressed, and it is desirable that it 
should be heated to near the oil flash-point, so that the oil may 
burn freely as soon as atomized. 

Ships in the Caspian Sea use steam, but are never far from 
land. Fuel may be injected under pressure and break up against 
an obstacle at the furnace mouth, or it may be vaporized by 
heat before reaching the furnace mouth. 

In Mr. Howden's modification, fuel is injected under pressure 
mixed with air previously heated by the waste chimney gases, 
and this system has been fitted to the North German Lloyd 
steamers Tanglier and Packman ; by Workman, Clark & Co., 
of Belfast. 

In the s.s. Murex already named, which arrived in the Thames 
in the spring of 1902 from a voyage of 11,800 miles, from Singa- 
pore via the Cape, the furnaces were never touched. Her coal 
consumption averaged 25 tons per day. With oil fuel the daily 
consumption is 16 tons only. The fuel supply arrangements, 
Fig. 9, consist of steam pipes A A A A, oil pipes BBB B, and 
burners C C C 0, hung on swivels D, so as to be adjustable in 
position, and to allow the doors to open upon the same axis or 
hinge centre. Coal can be reverted to, when the burner orifices 
F F F F are closed by the pivoted slides. In Fig. 10 is shown 

133 



134 



LIQUID FUEL AND ITS APPARATUS 



the brick work H H in the form of pillars and arches against 
which the flames first impinge. At K K are further baffle 
bridges to keep the flame from too severely striking the back of 
the combustion chamber carrying the stay nuts, the tube ends, 
rivet seams and parts liable to injury from excessive local heat. 
The form of burner is the 



Busden-Eeles 

type, Fig. 67, with adjustable annular orifices both for steam 
and oil (see Chapter XIX). They possess the quality of ad- 
justability while at work essential to secure the most perfect 




Fig. 9. Furnace Fronts of s.s. " Murex. 



possible conditions of combustion. The oil annulus is sur- 
rounded by a steam jacket, and steam enters the middle cham- 
ber and escapes into the furnace round the central stem, which 
is drawn back by revolving the end wheel and allows an annular 
spreading steam jet to escape round the flaring end of the 
stem. Oil finds its way to the little ring chamber immediately 
at the nozzle, and is directed down the sloping ends of the slide 
directly upon the steam jet which pulverizes it and spreads it 
in the furnace. The oil slide is drawn back by rotating the larger 
handle. 

Interchange of Coal and Oil. 

To permit the ready interchange of coal and oil the s.s. Trocas 
with fitted as in Fig. 11, the coal grates remaining and being 



MARINE FURNACE GEAR 



135 



covered with 8 inches of broken brick. The brickwork B, (7, 
and D always remains in place. 

To change over from oil to coal the burners are swung back 
to clear the furnace door, the broken brick is raked out, and 



'i r 



rrr 



in 



^T 




a 



a 



K 



R 





Fig. 10. Arrangement of Furnace Brickwork, s.s. "Murex.' 



ordinary coal firing resumed. In twenty-eight minutes after 
steaming full speed under oil the Trocas was again at full speed 
under coal. 

It is, however, found as the result of experience of long 
voyages that it is better not to let the firebars remain in when 



136 LIQUID FUEL AND ITS APPARATUS 

using oil, for, at the worst, the change over can be made in a 
few hours, and better results obtained from oil with the more 
approved arrangement. The general arrangement of the s.s, 
Trocas is that of Fig. 10. 

It is estimated by Sir Fortescue Flannery that the atomizing 
steam will amount to 0-2 pound per i.h.p. per hour. The waste 
is made up by large evaporators, usually in three interchange- 
able sections which should be worked steadily. 

Two burners in each furnace are found to give better results 
than one larger burner, being more easily adjustable and 
maintaining continuity of flame. There is also greatly dimin- 




j 



ti.Ts.j.i. 



Fig. 11. Furnace Arrangement or s.s. "Trocas.' 



ished chance of extinguishment of the flames by an accidental 
access of water from imperfectly dried oil. 

The Flannery -Boyd System for Steamships. 

The chief object of the system is to separate from the oil 
fuel the water which may have become mixed with it in any 
manner and also to enable oil fuel to be carried in ballast tanks 
or other compartments where water is usually carried. 

To get rid of the water two or more settling tanks are used, 
in which the oil remains a sufficient length of time to permit 
of the water depositing. In each tank is a heating apparatus 
to assist the action, for by heating the oil the water is more 
quickly deposited, owing to the expansion of oil being greater 
than that of water, and because the oil is made less viscous by 



MARINE FURNACE GEAR 



137 



heat. Two or more tanks must be used, so that while the 
water is being deposited in one tank the dried oil in the other 
may be fed to the burners. The system is applicable to anv 
system of burning oil. 



Oil Fuel 
^Arrangement op SeiWice Tank 

ON THE 

pL/iNNERy Boyo Patent SysieM 





N.B. SERVICE TANKS NUMBER 2 MAY BE MADE ROUND, SQUARE OR BUILT INTO SH1B 



1 




2 




3 








A. 






P 




7 




» 




in 




,, 




■H- 






I7i 








15 


ITEftH PIPEi TO BURNFSS 



Fig. 12. 



Fig. 12 shows the various pipe arrangements, the oil feed 
pump 3 drawing from the ballast tank 1 through a pipe 4 
and delivering by pipes 5 to the service tanks 22, whence the oil 
gravitates by way of pipes 7 to the oil burner supply pipes 9. 




m 

M 

<! 
En 

o 

O 
ft 

o 
8 B 



138 



MARINE FURNACE GEAR 



139 



Overflow pipes 13 carry back any surplus oil to the main tanks, 
and separated water is discharged by pipes 12. 

The service pipes are kept free of pressure by vent pipes 14, 
carried up several feet. 

The general arrangement of an oil ship is shown by a fairly 



Midship Section. 




Midship Section of Oil Tank S.S. New York. 



recent example, the s.s. New York, Figs. 13, 13a, built by the 
Palmer s Shipbuilding and Iron Company, Ltd., of Jarrow-on- 
Tyne. In this class of vessel all the seams and butts of the shell 
plating, decks, and bulkheads are riveted, and the rivets are 
spaced, for oil tightness, 3 J diameters centre to centre, instead 



140 LIQUID FUEL AND ITS APPARATUS 

of 4 diameters as required for water-tight work. Special care is 
also taken to avoid as far as possible any rivet passing through 
more than two thicknesses of plating. The vessel is divided 
into eight pairs of oil tanks with expansion trunks for each pair. 
There is a coffer-dam at the back of No. 1 tank, separating it 
from the power department. A small hold for miscellaneous 
cargo is placed forward by No. 8 tank, from which it is separated 
by a coffer-dam. The oil tanks are divided along the centre 
line of the vessel by an oil-tight bulkhead, so that there are 
really sixteen oil cargo tanks. The length of the New York is 
428 feet between perpendiculars, the breadth 54 feet 6 inches, 
and the depth 32 feet. The water ballast tanks extend the full 
length of the ship below the oil tanks. Coal bunkers are pro- 
vided on each side of the engine and boiler compartments 
and also forward of the boilers, between the boiler compart- 
ment and the after coffer-dam. 



The Orde System. 

In Figs. 14, 14a, 15, are shown various arrangements of oil 
fuel, burning by Sir W. E. Armstrong, Whitworth, and Co., of 
Newcastle-on-Tyne, according to the system of Mr. C. E. L. 
Orde. 

Fig. 14 shows the general arrangement for a water tube 
boiler. Steam, superheated in the casing by means of a pipe 
carried round the steam dome, is taken to a subsidiary steam 
header, whence branch pipes issue to five separate burners. 
Oil is fed by similar pipes from a second header supplied from 
the bunker or oil tank through a heater on the right. This 
contains exhaust steam, and heats the oil on its way to the 
burners. The oil is drawn off from the tank as in Fig. 14a, by 
means of a floating arm, which always takes the highest oil from 
an area which is heated by a steam pipe coil placed under the 
intake of the oil pipe. A small pump forces the oil to the distri- 
bution system, a relief pipe carrying any excess back to the 
pump suction. Air, heated in the ashpit through which the 
pipe is laid, is supplied to the burners by a separate pump on 
the left. The copper steam pipe to the float is flexible to allow 
for the float movement, and the float is kept steady laterally 
by a piece of angle iron bent to a circular form to suit the path 
of the float arm. Blow- through steam pipes are fitted for 
clearing the oil pipes when required. The atomizer, Fig. 15, 
is triple, oil entering through the centre passage, with needle 
regulating spindle. Steam comes outside the oil through an 
annular passage and air is introduced outside the whole, the 




x4l 




Suctk 



Stritch of'lflkter Separating Apparatus. 

Fig. 14a. Fuel On. Bunker. Draw-off Pipe and Float. 



142 



MARINE FURNACE GEAR 



143 



mixture being blown through the spreading orifice as spray. 
The oil does not come through as a solid jet into the com- 
bining nozzle, but as a thin annular shell jet easily atomized. 
The atomizer, however, differs from some others which admit 
air at the centre. The illustration shows the latest pattern 
(1911). 

Highly superheated steam is intended to be used (preferably 
600°F.). 

The annexed table from a paper by Sir F. Flannery, in the 
Transactions of the Institution of Naval Architects, gives a few 
results. 















Per cent. 


Ship. 


System. 


Oil per 
I.H.P. 

per hour. 


Coal 

per 

LHP. 


Heating 
Surface. 


I.H.P. 


of gain 
by use 
of Oil. 






lb. 


lb. 


sq. ft. 






F. C. Laeisz 


Korting 


1408 


1-93 


7,560 


2,200 


27-0 


Sithonia . 


Howden . 


1-065 


1-49 


6,924 


2,500 


28-6 


Murex . 


Rusden- 

Eeles 


1-3 

16 tons p. d. 


25 tons 
per day 


5,202 


— 


360 


Syrian 


>? >> 


1-32 


— 


2,480 


800 


— 


Khodoung. 


Orde . . 


1-08 


1-67 


2,700 


960 


35-5 



In each case, except the Sithonia, which had quadruple 
engines, the engines were triple expansion. 

Lancashire Boiler with Orde's System. 

The Lancashire boiler as arranged by the Wallsend Slipway 
and Engineering Company, for burning oil with or without a 
grate, is given in Fig. 16. 

A single injector is applied to each furnace door, the grate is 
covered with broken brick, and at the middle of its length 
a brick baffle is built, round and through which the flames 
escape, and after passing a low bridge at the rear of the grate 
escape unimpeded. 

Without a grate, the furnace is fitted with a brick oven and 
striking bridge, beyond which is a cellular baffle of brick 
which gives a final mixing to the gases before they are quite 
consumed. 

A gravitation tank is placed about 10 feet above the level 
of the atomizers, with suitable valves, vent pipe, overflow and 
gauge. The supply pipe to the atomizer has a strainer in its 
course. 

These various arrangements differ very little from those of 
other engineers, the chief object being the atomizing and the 
arrangement of the fire-brick oven and bridges. 




Fig. 15, Orde and Sodeau's Atomizer, Armstrong Whitworth & Co. 



144 




£ 



o 

ef o* 
H O 

w g 
3 o 

Hi 

fi 
O 



q co 



X45 



146 LIQUID FUEL AND ITS APPARATUS 



The Wallsend System of Oil Burning. 



In the latest practice of the Wallsend Slipway and 

gineering Co. 





En- 
the 

oil is injected into 
the furnaces (Fig. 
17) under pressure 
by m eans of 
pumps, no steam 
being used in 
atomizing the oil, 
but only steam to 
drive the fuel 
pumps and to heat 
the oil in the 
heaters. 

After the steam 
has done its work 
it is delivered to 
the condenser and 
there is no loss of 
fresh water. 

There are no air 
compressors o r 
blowers required, 
the only working 
parts being the oil 
fuel pumps them- 
selves, so that 
wear, tear and 
breakdowns are 
reduced to a mini- 
mum. 

The liquid fuel 
is drawn from the 
storage tanks by 
duplex pumps. 
On its way to the 
pumps the oil 
passes through a 
duplex filter, ar- 
ranged that each 
side can be cleaned 
whilst the other 
side is in use. 



MARINE FURNACE GEAR 147 

The pump delivers the oil first to a receiver of sufficient 
capacity to ensure its discharge to the burners under a steady 
pressure. From the receiver the oil passes through the main 
steam heater. 

The temperature of the oil on leaving the heater is recorded 
and the oil then passes through a discharge duplex strainer of a 
similar design to the suction strainer and thence to the burners 
(Fig. 18), to which are fitted special air distributors. These 
consist of an inner and outer cylinder having vanes fitted 
between them. 

These vanes are arranged specially and give a rotatory 
motion to the air and oil spray. 

Two sets of nozzles are supplied to allow a wide range of 
power being developed by the boilers. 

The air distributors are adjustable so that the amount of air 
entering the furnaces can be regulated to a nicety and complete 
combustion obtained. 

Tests carried out on this system by Professor Barr on Messrs. 
J. Howden & Co.'s works boiler at Glasgow showed 16-22 lb. 
of water evaporated per lb. of oil burnt from and at 212°F. 

As a result of Messrs. J. Howden & Co's experience with the 
system they have decided to fit the Wallsend System as shown 
in Fig. 17a in conjunction with their closed system of forced 
draught. 

In this and Fig. 17 it will be noticed that there is now very 
little brickwork in the furnace of a marine boiler, and that the 
whole circumference of the furnaces is available as heating 
surface. 

This is possible with the fine atomization and air mixture, 
combustion being well advanced before the conical spray reaches 
the furnace plates. When there are no firebars the whole of 
the furnace surface is efficient as heating surface and the lower 
part of the boiler is thus kept hotter than when the ashpit 
bottom is shielded by a grate. Each spray nozzle has its sur- 
rounding annular air passage with whirl vanes, and this keeps 
the outer trunk cool. A protecting face of brickwork is em- 
ployed as shown. 

The annexed table gives the results of the tests above re- 
ferred to and made on Messrs. Howden' s works boiler of 
11 ft. diameter X lift. 6 in. long with two 39 inch furnaces 
and a total heating surface of 1,358 sq. ft. The steam was 
stated to be dry, or nearly so. 1 

1 The dryness was tested by calorimeter, but the author places no 
reliance on any known system of taking samples of steam out of a 
steam pipe. The sample passed to the calorimeter cannot be known to 
be accurate. 




Fig. 18. The Wallsend Pressure Burner. 



148 



MARINE FURNACE GEAR 



149 



It will be noted that the weight of oil per hour figures out at 
nearly 46 lb. per square foot of cross section of furnace 
in trial 1, and 31 lb. in trial 2 with lighter draught. 
Reckoned on the longitudinal section of the furnace as though 
each furnace had 20 sq. ft. of grate area, as it might have 
with grates, the fuel per square foot per hour works out 
at about 23 and 16 lb. respectively, or a heat production per 
square foot of " grate " of about the equal of 30 and 21 lb. of 
coal. 



Summary of Results of Trials of the Wallsend Patent 

Liquid Fuel Burning System working with Howden's 

Forced Draught. 



Duration of trial . . . hours 

Number of burners per furnace . 

Class of oil used . . (Scotch) 

Calorific value (nett) of the oil 

B.T.TJ. 

Specific gravity of the oil at 60°F. 

Steam pressure . lb. per sq. in. 

Average temperature of feed 
water deg. F. 

Pressure of air entering furnaces 
in. of water 

Temperature of air entering fur- 
naces deg. F. 

Description of smoke at chimney 
top 

Temperature of gases at the foot 

of chimney .... deg. F. 
Weight of oil burned per hour lb. 
Weight of oil burned per hour 

per burner lb. 

Weight of water evaporated per 

hour . . lb. 

Weight of water evaporated per 

lb. of oil burnt . . . .lb. 
Equivalent evaporation from and 

at 212°F lb. 

Equivalent evaporation from and 

at 212°F. per sq. ft. of heating 

surface per hour . . .lb. 
Thermal efficiency of boiler . 



H 

One No. 18 
Pumpherston 


2 

One No. 16 

Pumpherston 


18,770 

0-868 

155 




18,770 

0-868 

155 


115 




120 


2| in. 




tin. 


190° 




185° 


Very lig 
none 


ht to 


Very light to 
none 


488° 
932 




420° 
633 


466 




316-5 


13,050 




9,000 


14-00 




14-22 


15-91 




16-22 


10-92 

82-3% 




7-55 

83-9% 



The arrangement of the Wallsend System to a marine boiler 
of Scotch type is given in Figs. 19, 19a, and the general arrange- 
ment for a water-tube boiler is given in Fig. 20. 




150 



152 LIQUID FUEL AND ITS APPARATUS 

The Korting System. 

In this system, as fitted to the Hamburg- American s.s. F. (X 
Laeisz several years ago, the water was first separated out of the 
oil which is raised by a pump, and heated to 60°C.= 140°F. 
by a heater on the suction pipe, and filtered before it reaches 
the pump valve, and thence delivered to a second heater, 
which raises its temperature to 90°C. = 194°F., and after a 
second filtration and under a pressure of thirty pounds per 
square inch, injected round a screwed needle, which causes the 
hot oil to spray itself. The bars are omitted, and the furnace 
lined in fire-brick and the air is admitted through adjustable 
perforated gratings. 

The front of the oven is a disc of fire-brick with a small open- 




Fig. 21. Furnace of s.s. " F. C. Laeisz," with Brickwork. Korting 

System. 

ing through which the spray is delivered and air is admitted. 
It this system the oil is made to spray itself and is sufficiently 
atomized by the pressure and the action of the screwed needle 
round which it escapes. 

The furnace of s.s. F. C. Laeisz is shown in Fig. 21 with the 
furnace lining and the brickwork of the combustion chamber 
also. In Fig. 22 the Korting sprayer is shown in section, with 
its spirally wound needle which throws the oil into rapid ro- 
tation and causes it to spread widely at the nozzle, exactly as 
in the case of the Korting water cooling sprayers. It was then 
considered essential to line the furnace in order to secure perfect 
combustion and insure that all the oil is vaporized before it 



MARINE FURNACE GEAR 



153 



reaches the chilling zone of unprotected water cooled plates, 
but later practice by the Wallsend Co. appears to have succeeded 
in securing com- 
bustion without 
smoke in an un- 
lined furnace as in 
Fig. 17. 

The diameter of 
the jet orifice is 
1 to 3 mm., and 
in later forms 
there is a crown or 
disc set round the 
nozzle and pierced 
with holes of 1-25 
mm. diameter, 

through which air is intrained. The output under a pressure of 
six kilos =84* 4 pounds, was as follows when tried at Cherbourg — 

Orifice .... 1 mm, 1 mm. 25 1 mm. 5 

Oil per hour ... 65 k. 100 k. 135 k. 

143 lb. 220 lb. 297 lb. 

Tried on the locomotives of the Vladi-Kavkaz Railway these 
atomizers with double jets sprayed 230 kilos =506 lb. per 
hour under a pressure of only 4-2 k. =59-8 lb. From the 




Fig. 22. Routing Atomizer. 




Fig. 22a. Korting Atomizer. 

trials made by the French Navy it appears that these 
mechanical atomizers work very regularly and, moreover, 
silently, if the oil is first filtered and heated to 80°C. == 176°F. 
They are recommended for getting up steam, the force pump 
being hand worked until such time as steam is produced 
sufficiently to work the pulverisers. 

M. Bertin lays stress on the benefit of supplying oil to a 
burner at a considerable pressure and at a high velocity, for 
even with air or steam atomizers the fine jet will atomize more 
easily, for an oil pressure of three kilos, for example, permits of 
a velocity four times as much as is given by a head of 2 metres. 



CHAPTER IX 

LIQUID FUEL APPLICATIONS TO LOCOMOTIVE BOILERS 

The H olden System. 

IN this system, the first to come into extensive use in Great 
Britain, the object has been to combine liquid and solid 
fuels so that either or both can be used indifferently without 
a moment's notice of the change. 

Mr. Holden, of the Great Eastern Railway of England, 
primarily devised his system for getting rid of the tars pro- 
duced by oil gas apparatus ; but he has used many liquids for 
fuel, including coal tar, blast furnace tar and oil, shale oil, 
creosote and green oils, astatki and crude petroleum. Loco- 
motives thus fitted are clean to work, make no dust, smoke or 
sparks, have little wear of tubes or fire-boxes and have little ash 
and clinker to remove. Steam can be raised rapidly, adjusted 
at an even pressure, and waste at the safety valve is prevented. 
Any boiler can be fitted for liquid fuel without alteration of 
furnace, though it is desirable to add a fire-brick lining on the 
tube plate below the arch. 

The fire is made up thin with coal and about 120 pounds of 
broken fire-brick. The ashpit damper is kept sufficiently open 
to maintain the fire bright. 

There is nothing striking to be seen from the footplate, with 
the exception of an extra fitting on the fire-box casing, carrying 
four steam cocks and two small wheel valves about the firedoor 
level on each side thereof. 

A hinged plate appears under the fire door, and on Hf ting this 
there are visible two holes, through the fire-box outer casing, 
leading into the firebox, and equidistant on each side of the centre 
fine 21 inches apart ; they are 5 inches diameter and 10 inches 
above the grate surface. In each hole is a ring of pipe per- 
forated on the front side so as to direct numerous jets of steam 
forward into the fire-box. In the latest atomizers this ring 
is not employed, the nozzle of the atomizer being enclosed in a 
box perforated on the face with several holes through which 

154 



APPLICATION TO LOCOMOTIVE BOILERS 155 

the spray jets issue at converging angles. These cause an 
induced current of air. In the centre of each of the rings 
is the nozzle of an injector. These are steam worked and inject 
oil into the fire-box, mixed with air, which enters at the rear of 
the injectors by an india-rubber hose connexion from the 
vacuum brake if this is used. 

The steam inlet to each injector is on the inside, steam com- 
ing by a single pipe, which branches off by square turns right and 
left to the injectors. Oil enters by separate pipes worked by 
two independent regulating wheel valves, which stand above 
the footplate at the fire door level. Each valve is thus inde- 
pendently adjustable, but both can be worked together, 
instantly to open and close, if necessary, at stations and other 
stops. Otherwise the oil apparatus is controlled from the four 
cocks mentioned above. One turns steam on to the injector 
supply ; another, by right and left branch pipes, turns steam 
to the air injecting rings ; and a third admits steam into a 
warming coil in the oil tank for the purpose of bringing the oil 
to a state sufficiently liquid to flow freely, and to be sprayed suffi- 
ciently fine. The fourth serves to blow back steam through the 
oil fuel pipes to the tank to clear any obstruction or to blow back 
oil which has cooled in the pipe or to warm the pipe, and to 
blow through the oil passages of the injectors. 

The mode of working is as follows : the engine comes up 
from the shed with the light coal fire with which steam has 
been made. It is clear and red, the fire-brick arch well heated, 
and the fire made up with brick lumps as usual. When de- 
sired to burn oil, steam is first set blowing through the injector. 
The delivery of the injectors is directly forwards and sideways, 
the nozzle having two orifices. No oil is sent against the fire- 
box sides, but only towards the brick arch and towards the 
middle of the box, the two inclined jets approaching each other. 
After the steam is turned on, the oil admission valves are slowly 
opened and the oil is sprayed and ignites at once, the whole 
firebox being filled with a dazzling white flame. 

There is now smoke at the funnel from insufficient air supply. 
This is instantly checked by turning steam into the ring jets 
which draw in a further large quantity of air through the five 
inch openings, and smoke can be reduced to any extent down 
to nil. This is a specially valuable feature in economy, for, 
while it is so desirable to prevent smoke, it is equally unde- 
sirable to admit too much air, and this can be regulated to a 
nicety, merely enough air to stop the smoke being injected, or 
even only enough to reduce the smoke to an occasional sus- 
picion of it. There need be no waste due to excess of air. 



156 LIQUID FUEL AND ITS APPARATUS 

The light coalfire is kept going by an occasional shovel of 
coal. 

Though the apparatus is simple, if it were possible for it 
to be put out of order in the middle of a trip, the fireman 
would commence to shovel coal upon the existing bed of fire, 
and the engine would run as an ordinary coal burner without 
a hitch or stoppage. 

On a trip, if steam is high, the injectors can be instantly 
stopped on arriving at a station, or, if the steam is low, con- 
tinued at full blast as when running, and the fire kept up to a 
maximum efficiency, and steam got up during the wait. There 
is less dependence on the blast pipe, and a variable blast nozzle 
is used, the simple movement of a lever in the cab swinging a 
hinged cap over the pipe top and reducing the nozzle from 
5J to 4f inches diameter for coal burning. 

Should any oil travel unburned so far as the brick arch, 
and even run down it, it cannot travel over the firebrick pro- 
tection of the lower tube plate without vaporization and com- 
bustion, hence this protection, which is the one slight difference 
from common practice, a difference, however, of no importance 
or injury to the engine's coal burning properties. 

There is no projection of any oil upon the fire-box sides, 
neither is there local intense combustion to produce local plate 
wasting. On the contrary, the whole interior of the fire-box is 
filled with flame, and no special ignition point, or rather, com- 
bution area, is apparent. Heating is therefore general, and 
temperature even. 

Though nominally a pound of oil has not the steam making 
power of two pounds of coal, nor perhaps could it be shown to 
have on a prolonged test ; yet in practice, one pound of oil is 
found to be equal to double the quantity of coal, owing to the 
facility of regulation and the saving at the safety valve and of 
the back pressure from reduced blast pipe resistance. Oil has 
the advantage of cleanliness and reduced labour all round, for it 
makes no unconsumable refuse, requires no stoking beyond 
the keeping up of the small bed of coal fire, which seems to 
be a good system where liquid fuel supplies are doubtful in 
quantity and uncertain in price, over any system of oil burning 
which rejects coal entirely. 

In the ordinary work of the Great Eastern Railway the run 
between London and Cambridge — about 56 miles — was made 
with one firebox full of coal made up ready for the run and un- 
touched. This brought the train to its destination, and if it 
were known that the engine would be shedded at once the 
steam might be pretty well reduced and the fire left to finish 



APPLICATION TO LOCOMOTIVE BOILERS 157 

nearly dead. Here came in the advantage of liquid fuel. Even 
if steam was down and the fire nearly out, the turning of a 
1 an die or two would put the engine in readiness to take out any 
train in five minutes after notice, and thus an engine may be 
worked to the economy it would be if about to be shedded, and 
yet be ready for a full-power run almost instantly. 

For lighting up, however, the fire started in a clear grate, as 
usual, and the month's average of fuel, including lighting up, 
was 12-2 pounds of oil per mile and 11 pounds of coal, or a 
total of 23-2 pounds of fuel. Nine other engines of the same 
class and the same range of duties averaged 34 pounds of coal 
per mile for the same month. Thus one pound of oil was 
practically equivalent to two pounds of coal. 

Mr. Holden states that for oil burning to be a success, the 
apparatus must be independent of any firebox alterations, or 
of anything which would prevent instant return to coal or 
solid fuel, or its use in lighting up. Hence his special injector 
to spray the oil without the use of special brickwork, hitherto 
common as a means of giving an extended hot surface. The 
several small ring jets which converge on the jet of oil, both 
spread and mix it with air and diffuse the flame, so preventing 
local heating. 

The injector, of gun metal, is clearly shown in section in Fig. 
23. Oil enters at the side some way back of the steam nozzle 
and outside this. Steam, therefore, comes inside a thin ring of 
oil at the mixing nozzle and through the inner tube comes the 
vacuum brake air which, expanding as it becomes heated, still 
further aids the breaking up of the oil into spray. The ring 
jets of steam induce a further supply of air on the exterior of 
all, and so is obtained an alternation of air, oil and air, which 
promotes admixture and thorough combustion. The inside 
of the injector is removable and can be replaced with 
a spare set in a few minutes when running. Removal of 
the brake hose connexion allows the injector nozzle to be 
cleared by a wire while actually at work, this being the main 
reason of the through passage which has been utilized — also 
for the purposes of the vacuum brake. The latest atomizer is 
that of Fig. 24 (1911). Compared with Fig. 23 and 25 it shows 
how comparatively little change has been made in the last 
nine years. The new pattern is found to use less steam. 
The ring jets of this pattern (Fig. 25) seemed to use a good 
deal of steam. 

In the newest pattern (Fig. 24) there is a small box end enclos- 
ing the nozzle, and the flat end of the box has seven perfora- 
tions inclined to each other so as to give a converging jet. The 







158 




159 



160 LIQUID FUEL AND ITS APPARATUS 

oil, air and steam are mixed in the box and issue together. 
Small supplementary steam jets issue from small holes as 
shown at the base of the nozzle box. 

The brackets of the oil regulating valves are movable verti- 
cally. The two brackets are connected to a hand wheel common 
to both, and dropped by a single movement of the wheel, thus 
shutting off both oil valves and putting them again in action 
without varying their individual adjustment. Later arrange- 
ments differ somewhat, the combined motion being given by a 
lever, as in Fig. 26. 

This lever is used for the station stoppages, after which each 
injector can be set going again exactly as before the stop, so 
dispensing with fresh regulation. 





Seciis* A 3. Section C P 



•Fig. 25. Atomizer. Old Form, JIolden System. 



In locomotive work, the absence of a bed of incandescent 
fuel on the grate is a cause of very serious temperature range 
in the firebox when the oil is shut off at stops. Where a solid 
fire is maintained on the combined system, there is always an 
incandescent fire to prevent undue cooling when the oil is 
stopped, and this is a valuable feature apart from the question 
of lighting up in the ordinary way and the power of using 
solid fuel if necessary at any time so to do. 

Fig. 24 is the latest form of atomizer. 

The valve B used for regulating the flow of the oil fuel is of 
special construction, found desirable after many attempts with 
different forms of cocks and valves. To pass regular quantities 
of thick viscous fluid through the " crooked passage " formed 
by the half open plug of a common cock is impossible, and 
some form of " Straightway " valve is necessary. In the 




181 



162 LIQUID FUEL AND ITS APPARATUS 

example, a small reservoir of oil is formed by the body of the 
valve, and a tube with a slit in it is moved up and down inside. 
The proportion of cut exposed in the oil reservoir regulates the 
supply. With this valve very fine adjustments in the flow of 
oil are possible. 

The Holden apparatus is now largely used on stationary, 
locomotive and marine boilers, but its application on English 
railway work has been reduced by the comparative scarcity of 
oil since the demands of the Navy have absorbed so much. In 
short, liquid fuel is not yet produced to supply the demand. 

In Fig. 27 is shown the firebox, about 8 feet long, of an 
American locomotive. The tube plate and sides are lined with 
brick, and there are two air inlets at the bottom of the box 
opening into the ash pit, which has the usual front and back 
dampers. In these narrow boxes there is only room for one 
atomizer. Oil alone is intended to be used in this furnace, and 
the area of brickwork is necessarily larger than in the mixed 
system, where the bars are covered with more or less self- 
incandescent fuel. The fire-brick arch, but slowly adopted 
in American coal burning engines, is of necessity a part of the 
oil burning furnace. In some locomotives there is also a small 
arch over the atomizer to protect the fire door. In certain 
locomotives with still longer boxes there will be a wall of 
brick about 6 feet in front of the atomizer, and the arch springs 
from this wall, so that there is a combustion space between the 
wall and the tube plate. 

With Texas oil the Great Eastern locomotives, class 1900, 
have hauled fast trains on a consumption of 24-7 pounds of 
coal tar per mile plus 9-6 pound of coal for lighting up, etc., as 
against 40 to 45 pounds of coal. On a test run with a train of 
620 tons a four-coupled passenger engine consumed 31 pounds 
of Texas oil per mile. These engines were fitted with air heating 
arrangements. On the Japanese Government railways, Borneo 
oil on the Holden system showed an evaporation as high as 
14-42 and averaged 12-6 the year round as against 6-4 pounds 
for coal. 

An important item is the lengthened life of the internal fire- 
box. After some service the sides of an ordinary firebox 
present a series of convex surfaces between the stays, which are 
subjected to abrasion by the small ashes, sparks, etc., drawn 
from the fire by the action of the blast. As a result of this 
wearing away of the surface of the plate, it gradually be- 
comes thinned, and eventually cracks develop between the stay 
holes, with the consequence that the box must be patched 
or renewed after a comparatively short existence. With oil 



APPLICATION TO LOCOMOTIVE BOILERS 163 

fired engines an extension of time of some 50 per cent, can be 
secured, as no such destructive action exists. These remarks 
on abrasion apply equally to the tubes, smoke box, chimney, 
etc., and the economies in this direction are of considerable 
value when large numbers of locomotives are affected. 





Bui ner 



Fig. 27. Firebox of American Oil-Burning Locomotive. 



With oil burners the fire is of equal intensity, and as clean 
at the end of the day as at the start, and an engine can be run 
indefinitely as regards the fire. 

The average life of copper fire-boxes of five G.E. Rly. engines, 



164 LIQUID FUEL AND ITS APPARATUS 

No. 754 to 758, with coal, was found to be 5| years, and that 
of two other sister engines, No. 760 and 765, using liquid fuel, 
was respectively 8 years 4 months and 8 years. 

In fitting these burners to ordinary stationary boilers they 
are connected by means of pipes to a hinged joint or trunnion so 
arranged that when the burner is swung out of position, the 
supplies of steam and oil are cut off, so as to prevent the risk of 
fires in the stokehold. 

Where, as often the case, oil contains water in such quantities 
as to extinguish the fires there is considerable danger. The oil 
following after is — if the furnace temperature is sufficiently 
high — violently exploded, or, if the furnace is allowed to become 
too cold, the oil falls through the ashpits and on to the stoke- 
hold floor, where it spreads out into a thin film probably at a 
temperature approaching the flash point, and therefore in a 
highly inflammable state. 

The specific gravity of most fuel oils being 0-86 to 1 the rate of 
settling at low temperatures is very slow, but the difference 
in the specific gravity becomes much more marked if the 
temperature is raised, and very usual practice has been to heat 
up the whole contents of the oil bunker to such a temperature as, 
without approaching the flash point of the oil, will make the 
density difference sufficient to accelerate the settling. 

The objection to this is that a large amount of heat is required, 
the radiation surface of a bunker of any size being considerable ; 
the heating process is slow, and unless completed before any 
of the contents are drawn off, the lower layers of the tank will 
consist either of pure water or oil with a large percentage of 
water mixed up with it. 

To obviate this, a floating suction is used consisting of a long 
pipe pivoted upon the side of the bunker or tank, and guided 
in the vertical plane by means of a tee or angle iron set to 
correct radius. 

The suction pipe has a small steam-pipe led along its side, 
which terminates in a coil immediately below the suction open- 
ing. The steam passes through this and heats the oil immedi- 
ately below the orifice, and this oil rises into the j)ipe and leaves 
the water behind. The float is proportioned and arranged to 
keep the mouth of the pipe about 6 inches below the level of 
the oil in the tank. 

This apparatus is certain in action and requires but little 
heat, since this is only applied to that portion of the oil immedi- 
ately under the mouth of the suction pipe, and there is little 
radiation from the bunker side, and the heated oil at once 
moves off to be used while still hot. 





PFP? 



Jl— 9 SL 




About 20 barrow loads make one cubic yard. An ordinary cart 
holds about |-| cubic yard. 



165 



166 LIQUID FUEL AND ITS APPARATUS 

Fig. 28 shows the application to a locomotive with fire-box 
3 feet 4| inches wide. For a smaller fire-box one atomizer only 
is necessary. 

The apertures in the fire-box are made by screwing a copper 
ferrule into the tapped plate and beading over at the ends ; 
into this is drifted a wrought iron ferrule, which makes a per- 
fectly tight joint. 

The nozzle of the atomizer is placed about § in. above the 
centre of the aperture, and the face of the ring £ inches from 
the front of same. 

When liquid fuel is used alone, steam is first raised in the 
boiler by a wood and a coal fire to 25 pounds or 30 pounds 
pressure, the fire is levelled and covered with a layer of broken 
fire-brick of not more than 3 inches cube, spread thinnest 
about the centre of the fire-box, and well packed round the 
sides and corners. A few pieces of waste or wood are thrown 
in to cause a flame before the fuel is introduced. 

An air heater formerly was used, but has been abandoned in 
recent practice. 

The regulating gear is so arranged that a simple movement 
of the lever closes both oil valves without affecting their 
separate adjustment when open. 



CHAPTER X 

LIQUID FUEL APPLICATION TO STATIONARY AND OTHER BOILERS 

The Lancashire Boiler. 

FIG. 29 shows the arrangement of Holden's Burners on 
a Lancashire type boiler. The burners are placed at the 
front of the brick lined extensions, to which heated air is con- 
veyed from large tubes passing down the outer flues. The 
fire-brick construction is simple and easily introduced for an 
ordinary sized boiler with a grate of, say, 7 feet long. A strik- 
ing bridge pillar with inclined face is built up about 2 feet 
6 inches inside the furnace ; next, a screen with large clear 
opening about 1 foot 6 inches behind the former ; and finally, 
a second screen with oblique perforations to direct the gases 
along the inner surface of the flue. The central portion of this 
last screen is recommended to be built solid. On boilers thus 
arranged, with fair working conditions, an evaporation of from 
14 to 15 pounds of water per pound of Texas fuel oil (from and 
at 212°F.) is readily obtained. 

On a large boiler of this type burning north country " smalls " 
and evaporating only 6-5 pounds of water per pound of coal, 
the Texas fuel oil has secured an evaporation of 15-25 pounds of 
water per pound of fuel. 

If desired the fire bars are left in and covered by a layer 
of fire-brick or chalk as a base for the fire in case it may be 
necessary to return to solid fuel at any time. Any internally 
fired boiler may be treated by either method. Where the 
bars are left in there ought to be a damper fitted to the opening 
of the ash-pit to regulate the admission of air. 

In these furnaces the injector is placed about 8 or 10 inches 
above the grate surface and about J inch above the centre of the 
4-inch opening cut through the furnace door. The injector 
is inclined so as to point to the second or third brick from the 
top of the bridge. Dry steam, perferably superheated, is 
admitted. 

Generally, in the firing of internal furnace boilers, the fuel is 
blown in parallel with the grate surface and 8 to 10 inches 

167 




168 




169 



170 LIQUID FUEL AND ITS APPARATUS 

above it. In the large vertical boiler the atomizer is usually 
placed below the fire-door opening, but in small vertical boilers 
it must be placed through the door. In either case the opposite 
half circle of the furnace must be lined with fire-brick to the 
height of about half the furnace diameter to form the necessary 
incandescent surface on which any unburned oil can strike. 



VtL-y 




The Water Tube Boiler. 

For the water tube boiler without grate bars the arrangement 
of Fig. 30 is employed, there being' an additional arch of fire- 
brick brought forward from the bridge to prevent too early a 
passage of the gases among the tubes. The author would 
extend this (and also the first arch) further than shown in Fig. 
30 ? it being impossible either with coal or oil to secure smokeless 

results where the hydrocarbon gases 
pass too quickly among cold tubes. 
Nor is there space and time for such 
complete combustion as is desirable. 
The steam blast may be made less 
intense when oil fuel is used by the 
Mac Allan movable cap (Fig. 31). 
This is folded over the blast pipe 
orifice, which it reduces from 5| to 4| 
inches diameter. 

The position of the atomizer is 
important. If too high the combus- 
tion is vibratory, and an intolerable 
humming sound is produced by the many rapid explosions due 
to non-continuous combustion. The oil fire must be along the 
plane of the coal fire for the best results, and not too high 
above it. 

Owing to its large proportion of hydrogen, the production 
of carbon dioxide is less, and this is held to be an advantage 
of liquid fuel for working tunnels, and the Arlberg tunnel was 
so worked by 32 engines. It must not, however, be over- 
looked that hydrogen destroys three times as much oxygen 
as is destroyed by a pound of carbon, and produces but little 
more calorific effect per pound of oxygen consumed, so that 
it is equally destructive of the vital properties of the air and 
introduces an excess of nitrogen in place of an excess of carbon 
dioxide. The physiological effect of the carbon dioxide is less 
to be feared than the absence of oxygen which it implies. 
Too much, therefore, should not be made of this supposed 
advantage of liquid fuel, the danger being due to the absence of 



Fig. 31. Mac Allan Vari- 
able Blast Cap. 



APPLICATION TO STATIONARY BOILERS 171 



oxygen. The Arlberg tunnel is now electrically worked. 
No very large installations have been made lately, owing to the 
difficulty in obtaining a large and continuous supply of oil at a 
price low enough to meet the competition of coal. But many 
heavy locomotives have been fitted for special work on moun- 
tain sections with many long tunnels, as on the Italian State 
Railways. It is particularly desirable to avoid smoke in 
tunnels. 

Locomotive Boiler. 

Fig. 32 is the fire-box used for liquid fuel on the Southern 
Pacific Railroad, the oil being sprayed into the front of the fire- 
box below the mud ring and under the usual brick arch and 
directed against a sloping brick lining of the back plate. The 
sides of the box are 
cased in bricks, and 
there are openings 
for air in the brick 
bottom to admit air 
under the flame. A 
central brick arch 
baffle is thrown 
across the middle 
of the fire-box, and 
an arch is thrown 
across just below 
the fire-door. The 

plates of the upper part of the box are bare, and the results 
are said to be satisfactory. 

According to Mr. Holden the fuel tank should be above the 
level of the atomizers. This is a point with which all do not 
agree ; some consider that the fuel ought to be pumped to 
the atomizers, and no oil should be able to flow by gravity 
with the attendant risks in case of rupture. 

Unless an independent source of steam is available, steam 
should be raised in the boiler by an ordinary fire to a pressure 
of, say, 25 pounds, when the liquid fuel apparatus may be 
started. 

Oil burners must not be started before there is a flame in the 
furnace ; if doubtful, a few pieces of wood or some oily waste 
should be set alight in the furnace before applying the oil. 

The above rules are applicable to all systems of oil burning. 
A common danger is the risk of gases accumulating in the fur- 
nace and leading to explosion when the dampers are opened 
and flame produced. As with coal, the accumulation of gas 





Fu 



32. Locomotive Fire-Box for Oil Fuel 
Southern Pacific Eailroad. 



172 LIQUID FUEL AND ITS APPARATUS 

may be prevented by drilling a two -inch hole near the top of the 
damper, so that when the damper is closed there is always a 
vent through it which will stop any accumulation of gas. 

The atomizing agent, whether steam or air, should be hot ; 
high pressure steam is better than low pressure steam ; the 
tendency is to force the oil forward at a considerable pressure 
to the burners and compel it to escape, by a fine opening, there- 
by probably tending to atomize itself somewhat. 

The practice in America generally is towards pumping oil 
to the burners rather than allowing it to flow by gravity. 

Air at a moderate pressure appears to be as competent to 
atomize oil as steam at a high pressure. No explanation of 
this is given, but it is partially due to the greater density of air 
and probably in part to the fact that air is a supporter of 
combustion and induces earlier combustion or ignition. 

The Meyer System. 

This is shown in Fig. 33, and is a modification of the Korting 
system. Oil is supplied by the Korting system and air is ad- 
mitted through specially placed blades in an extension of the 
furnace front, the air being heated in a surrounding jacket, 
which is arranged with spiral divisions. The air is delivered 
to the surface in a whirling manner, and the system has been 
at work on several Dutch steamers with success and similar 
general types of apparatus have been running in Roumania. 



The Mixed System of Coal and Liquid Fuel Combustion 

There is more in the mixed system than mere convenience. 
The simultaneous use of solid and liquid fuel in the same furnace 
modifies the conditions for each. 

For coal the efficiency of combustion is better ; for oil the 
heat is better utilized. 

Combustion on the grate may be imperfect, but the oil 
atomizer so mixes up the gases from the grate with the air 
admitted through and above it, that combustion is much 
improved and the excess of air is used by the oil. 

Where the oil is only a fifth of the coal, the coal equivalents 
of the oil appears enormous. 

According to M. Bertin, where 5 kilos, of coal would ordinarily 
develop each 7,800 calories, they will produce 9,200 calories, a 
gain of 7,000 calories. The excess of air supplied with the 5 
kilos, of coal would be 20 cubic metres, and this would suffice 
for the added kilogram of oil, which would produce 11,000 




ItH ! 

n' ' 




tin ' 

k-|LJ 1 


£M 


'• 1/ — r ' — ' 


o Br 


«r^T^ 


W 




173 



174 



LIQUID FUEL AND ITS APPARATUS 



calories with no further air supply. A total of 18,000 calories, 
compared with the original output of 7,800 calories per kilo, 
of coal, makes the ratio of oil to coal appear 2-31. Obviously 
a part of this is due to coal, but it may fairly be credited to the 
system. 

The limit of perfect use of air is found when the oil is one- 
third of the coal, and the ordinary four cubic metres of excess 
air still furnishes the theoretical 11 cubic metres for the oil : 
the apparent equivalence of coal and oil becomes — 

1,400 x 3 + 11,000 



7,800 



= 1-95 



These ratios are not perhaps secured in practice, but serve 
to point to the possible advantages of the mixed system and 
what should be aimed at. 

With half and half coal and oil the ratio becomes 1-77, 
a figure that has been approached in certain experiments at 
Indret. Ratios of 3 and over, what have been claimed, cannot, 
as Mr. Bertin says, be justified on any hypothesis. Nor is the 
total consumption of the oxygen supplied at all closely ap- 
proached in general practice. 

The proportion of free oxygen to carbonic acid is an indi- 
cation of the excess of air admitted. The ratio of the air ad- 
mitted to that used is — 

C0 2 + . . O , , 

— ^~ = 1 + j^r-per volume, and 

C0 2 + 20-8 , 

~ N-~=79^ perV ° lume - 

These figures neglect the hydrogen. 

With coal burned at the rate of 100 kilos, per metre 2 of grate, 
if the oxygen measures 8 per cent., and with 200 kilos., say 
5 per cent., the fire is too thin or the draught too great. With 
1 or 2 per cent, of carbonic oxide the fire is too thick and the 
draught poor. Both oxygen and CO present together indi- 
cate bad furnace arrangements. 

A test at Indret of the trial boiler of the Jeanne d'Arc with 
coal alone gave the following results — 



Coal per hour 


Percentage in volume. 


l + o£ 


grate. 


co 2 . 


CO. 


O. 


N. 


90 k. 

140 

200 


11 
11 
13 


1 
1 

0-5 


6 
5 
4 


82 
83 

82-5 


1-54 
1-45 
1-30 



APPLICATION TO STATIONARY BOILERS 175 



The same boiler on the mixed system gave the results below- 



Per hour per metre 2 
of grate. 


Air 
Pressure. 


Percentage of Gas. 


1 + ro- 


Carbon. 


Petroleum. 


co 2 . 


CO. 


0. 


N. 


co 2 


75k. | 
100 | 

150 J 


37 k. 

30 

37 

50 
66 
35 
55 

75 


10 mm. 

10 

10 

20 

25 

25 

30 

40 


10 

10 

10 

8-5 

8-5 

11 

11 

11 












8 

8 

8 

9-5 

9-5 

7 

7 

7 


82 

82 
82 
82 
82 
82 
82 
82 


1-80 
1-80 
1-80 
212 
2-12 
1-64 
1-64 
1-64 



With oil alone Mr. Orde found as below- 





co 2 . 


CO. 


0. 


N. 


***& 


Test No. 1 

Test No. 2 


13-2 
12-6 






3-6 
4-0 


83-2 
83-4 


1-27 
1-35 


Average 


12 





3-8 


83-3 


1-285 



a better result, after all, than the mixed system produced. 

In calculating the apparent effect of mixed fuel, M. Bertin 
assumes the case of a boiler working 1 hour and a weight of water 
= a per kilo, of coal ordinarily, 
b = the water evaporated per kilo, of mixed fuel, 
x = the evaporation attributed to one kilo, of oil, 
C = weight of coal burned per metre 2 of grate, 

*-* J 3 Oil ,, ,, ,, ,, ,, 

The vapour produced by C + D of mixed fuel, assuming a 
to be as in the ordinary coal fired boiler, will be Ca + T>x. 
Then per kilo, of mixed fuel we have 

D)b 



Ca + T>x , ' . , . (C 

— — -_- = 6, which gives x — - — 
O -j- D 



D 



C? =6 +£<&_«), 



Whence, if R is the ratio of oil to coal, we have 

b . C /& 



R 



a a T) \a J 



Tests in the Furieux made to determine R gave the following 
results — 



D 

C 


a 


X 


a 


0-00 
0-45 
0-64 


9-05 
9-05 
9-05 


11-34 
14-2 


1-25 
1-56 



176 



LIQUID FUEL AND ITS APPARATUS 



The figure 1-56 was greater than the figure found for oil 
used alone, but was not confirmed by tests at Cherbourg of a 
Godard boiler with too forced a draught and badly arranged 
oil sprays, for the effect & of the mixed fuel was even inferior 
to that of coal alone, which shows how much the efficiency 
depends on arrangements. 

The value of R was sought at Indret by Mr. Brillie in a series 
of tests extending from the end of 1896 to early in 1900, in view 
of applying mixed firing to boilers of Du Temple Guyot type. 

The atomizers had air induction passages as in the Orde 
atomizer, Fig. 15, but no air heating. The names kept short 
and the heat kept well in the furnace, and high values of R 
were reached, as 1-6 for a rate of combustion of 100 kilos, of 
coal and 50 kilos, of oil per metre 2 of grate. 1 

The tests, however, were too short for exactitude. 

Other tests made only upon engine power are, however, 
available. 
Let c be the coal per horse power ordinarily. 



,, d ,, oil ,, ,, ,, 
Then d takes the place of c 
horse power so that 



in the mixed system. 

J5 5J 55 

e in the production of one 



R = 



d 



The following table is a resume of Navy tests on the loco- 
motive type of boiler or torpedo boat No. 109 at Cherbourg. 



Air pressure. 
Coal alone . 

c, , \ Petrolm. 
System j Total je+d 

, Equivalent =R =9=£ 
d 



d. 



1st Series. 



15mm. 
1,337k 
' 979 
379 
1,358 

0,94 



13mm. 

1,337k 
914 
388 

1,302 

1,09 



12mm 

1,337k 

581 

494 

1,075 

1,53 



2nd Series. 



25mm. 

1,354k 
713 
405 

1,118 

1,58 



26mm. 

1,354k 

721 

474 

1,195 

1,33 



29mm. 

1,354k 
652 
655 

1,307 

1,07 



3rd 

Series. 



50mm. 
1,506k 

1,219 
434 

1,653 

0,66 



The interest lies in the falling off at high pressures, the 
furnace being too short satisfactorily to burn the oil at such 
rapid draught. 

Where 60 kilos, of oil were used to 80 kilos, of coal with draught 
but little forced, R was found to be 1 -5, and the mixed system 
took the place of forced draught, with a result equal to the 
combustion of 170 kilos, of coal only, a result thought very 
encouraging. Very discordant results were obtained on the 

1 Kilos. per juetre 2 ^5=pounds per square foot nearly. 



APPLICATION TO STATIONARY BOILERS 177 

Milan, the Surcouf, the Pakin, and the Forbin. On the Milan 
especially oil proved very unsuitable to the furnaces of the 
Belleville boiler, as might be anticipated. On the Surcouf, 
on the contrary, the result of mixed fuel was to reduce total 
fuel consumption nearly to half that of coal alone. 

M. Bertin does not express any final opinion on mixed sys- 
tems, but claims that where employed it is essential to success 
that all the details should be simple so as to avoid the danger of 
error on the part of a little-trained personnel, such as the open- 
ing or closing of certain valves, always in their power to do. 

Generally little information is public on liquid fuel in any 
Navy. Nobody knows why a secret is made of it, for the 
efficiency attained with liquid fuel outside naval practice is 
such that better results are scarcely likely to have been attained 
within it. 



CHAPTER XI 

RUSSIAN AND AMERICAN LOCOMOTIVE PRACTICE 

The Baldwin Co.'s System. 

THE Baldwin Locomotive Co. consider that, while opinions 
upon atomizers differ as to central jet burners such as 
the Urquhart, the relative position of the oil supply and other 
details, their own burner (Fig. 34) is a satisfactory one, and 
has been applied to many locomotives in Russia and the 
United States. 

It is rectangular in section, with two longitudinal passages, 
the upper one for oil, the lower one for steam. The oil is 
regulated by a plug cock on the feed pipes, the handle of which 
extends to the cab within easy reach of the fireman. 

Steam is admitted to the lower part of the burner through a 
pipe so connected to the boiler as to ensure dry steam. The 
control valve is in the cab close to the fireman's seat. A free 
outlet is allowed for the oil at the nose of the burner ; the 
steam outlet, however, is contracted at this point by an ad- 
justable plate which partially closes the port, and gives a thin 
wide aperture for the exit of the steam. This wire-draws the 
steam increasing its velocity at the point of contact with the oil, 
and giving a better atomization. A permanent adjustment of 
the plate is made for each burner after the requirements of 
service are ascertained. The moving of the plate is not then 
required except for cleaning purposes. The oil, as it passes 
through the burner, is heated by the steam in the lower portion, 
and flows freely in a thin layer over the orifice. It is there 
caught by the jet of steam and completely broken up and ato- 
mized at the point of ignition, and carried into the fire-box 
in the form of vapour, where it is thoroughly mixed with air 
and burns freely. 

It is computed that one inch of breadth of slit will serve for 
100 square inches of cylinder area, so that the breadth of a 
burner is B = D 2 x 007854. As only one burner is used, 

178 



AMERICAN LOCOMOTIVE PRACTICE 



179 




Atomizer. Baldwin Locomotive Co. 



American fire-boxes being narrow, it is apparently the case 
that one cylinder is intended to be taken, and not the area of 
both cylinders. D = diameter of cylinder. 

Large oil-pipes deliver a full supply as far as the regulating 
cock, to permit of fine 
adjustment of which its 
orifice is not circular 
but square, with the 
diagonals as in Fig. 35. 
The necessary changes 
to fit an engine to use 
liquid fuel are shown in 
Fig. 36. The atomizer 
is attached below the 
mud ring, and the spray 

is directed upwards into the fire-box, which is fitted with a 
brick arch, a liner of fire-brick and a base filling the front 




Fig. 35. Oil Regulating Cock. 
Baldwin Locomotive Co. 




ISO 




to 



181 



182 LIQUID FUEL AND ITS APPARATUS 

half of where the grate usually is placed. A small hearth 
is placed to catch any drip from the burner, and from the 
lower corner of the bridge there is built, to protect each side 
sheet, a triangular wall of bricks extending with its lower point 
to the back plate. The side walls form the sides of the fire- 
brick combustion chamber. The " ash-pan " is retained with 
its air dampers to admit air below the fires, and the dampers 
should shut tight. The inner side of the fire-door is lined with 
a plate of fire-brick. 

The latest form of fire-box (1911) is that of Fig. 37. This differs 
but little from that of Fig. 36, which represents a coal fire-box. 
The arch is kept low and the upper space of the box is large. 
It is recommended not to leave too little space between the 
arch and the crown sheet ; otherwise the flames will be too 
severe upon the crown sheet and generate too severe a local 
heat. The ashpan is of modified form as shown. The weight 
and volume of oil for a given mileage will be about half that 
necessary for coal. 

A report of the Committee of the American Railway Master 
Mechanics' Association says — 

Fuel oil can be used in almost any form of fire-box, the best 
place for the burner being just below the mud ring, spraying 
upward into the fire-box. In some recent experiments with 
oil of 84° gravity, 140°F. flash, and 190°F. fire test, in which 
the boiler had 27 square feet grate area and 2,135 square feet 
of heating surface, 8 per cent, being in the fire-box, it was found 
that there were about 39 pounds of oil burned per square foot 
of grate area, about 0-45 pounds per square foot of heating 
surface per hour, the equivalent evaporation from and at 212° 
being about 12 J pounds of water per pound of oil. It was also 
computed that there should be about one-third of an inch 
width of burner for each cubic foot of cylinder volume. 

Or volumes of both cylinders in cubic feet -f- 3 — width of 
burner in inches for ordinary locomotives. For compound 
engines the amount of steam is 10 per cent, and of fuel 20 per 
cent, less, and in the foregoing formula only the h.p. cylinder 
volume ought to be considered. 

For compound locomotives a guide to an approximate idea 
of the value of oil fuel as compared with coal is as follows :— 

Cost of coal per ton (of 2,000 lb.) + cost of handling (say 50 cents) 

X 10-7 X 7 

2,000 x evaporative power of coal 

= Price per American gallon at which oil will be the equivalent 
of coal. To find the price per English gallon multiply by 1 2. 



AMERICAN LOCOMOTIVE PRACTICE 



183 



In these computations the cost of both oil and coal is con- 
sidered at the engine, and not at the place of purchase. 

The weight and volume of crude petroleum based on a 
specific gravity of 0-91, which is about the average of the Texas 
oil, as well as that received from South America, is given below. 



WEIGHT AND VOLUME OF CRUDE PETROLEUM. 



Pound. 


U.S. Liquid Gal. 


Barrel. 


Gross Ton. 


Imp. Gal. 


1 

7-6 

319-2 

2,240-0 


•13158 
1-00 
42-00 
294-720 


•0031328 
•02381 

1-00 

7-017 


•0004464 
•003393 
•1425 
1-00 


•1096 

•83 

3500 

245-60 



For convenience in obtaining the correct approximate weight of 
oil, the gravity conversion table, No. XIV, may be useful. 

In American practice where railroads are so dirty with ash 
and cinders thrown from the locomotives by the powerful blast 
employed, oil should give an advantage to any line adopting it 
that cannot be so securely counted on in Great Britain, where 
ash throwing is less prevalent. 

Oil puts a stop to the choking of the tubes of the boiler and 
permits tubes to be employed smaller than now admissible on 
account of liability to choke. 

Tubes of one inch diameter might be used if enough could 
be got in to give the requisite area. 

The economy of oil is not merely a question of fuel economy. 

Table No. XI gives the economy of oil at its relative value 
compared with coal on both the fuel account and all ascertained 
economies, the second value being based on 1 pound of oil 
being worth 2 of coal in place of If, as on the mere fuel account. 
The extra economies include repairs on locomotives and ash 
handling. 

Dr. Dudley's formula for relative price is — 

(V = price of oil per barrel. 
W= weight per gallon in pounds. 
N = gallons per barrel. 
R — ratio of oil to coal = If or 2, 

according to conditions. 
\C = price of coal per ton of 2,000. 

For tons of 2,240 lb. use this number in the numerator in 
place of 2,000. The weight W multiplied by N will be the same 
in either American or English gallons, and the barrel is always 
the same, so that only the pounds per ton need be changed, 



2,000 x P 

W x N x R 



C : where 



184 LIQUID FUEL AND ITS APPARATUS 

the price of coal and oil of course being given in the same 
equivalents, either dollars or shillings. 

Hence P - WxNxRxC 

~~ 2,000 (or 2,240 for long tons). 

The Baldwin Co. do not recommend crude oil : it is more dan- 
gerous ; it has an exceedingly unpleasant odour, and it is not 
so economical. Crude oil contains more or less volatile matter 
which vaporizes quite readily. With the necessary use of 
lanterns and open lights round about locomotives, there would 
be more or less danger of explosions. In the case of a wreck, 
if the oil tank was ruptured, it would be almost impossible to 
prevent a fire. As to the odour of the crude oil, it would cer- 
tainly be extremely unpleasant to ride behind a locomotive 
fed with Lima crude oil. Crude oil is not so economical as 
reduced oil, because oil is sold by volume, and a gallon of crude, 
instead of weighing 7-3 pounds, weighs from say 6-25 to 6-5 
pounds, and, as the heat is proportionate to the weight, a barrel 
of crude will not give so much heat as a barrel of reduced oil. 
The oil used on the Grazi-Tsaritzin Railway, and believed 
to be quite safe to use, is an oil not below 300°F. fire-test. 
Crude oil can be used on stationary boilers, where it is kept in 
tanks and brought to the boilers in pipes. 

The arguments appear sound, in view of the disastrous Ameri- 
can experiences of burning railway wrecks, and the English 
experience at Abergele ; but all crude oils are not so unpleasant 
as the Lima oil referred to, and the odour should not live 
through the furnace. Still the fire risk of crude oil, with its 
volatile constituents left in, is to be avoided. 

In experiments on the Pennsylvania Railroad, it was found 
with oil at 30 cents per barrel, that it cost nearly 50 per cent, 
more to take the same train of cars 100 miles by means of oil 
than by means of coal. 

The Urquhart System. 

To the late Thomas Urquhart, of Dalny, Scotland, the former 
Locomotive Engineer of the Grazi-Tsaritzin Railway of Russia, 
is due the first notable success in liquid fuel combustion. 1 

Urquhart brought the system to the notice of engineers in a 
paper read at Cardiff in 1884. 

According to this paper, the percentage of astatki in Russian 
oil is 70 to 75 per cent., while Pennsylvania oil contains but 
25 to 30 per cent., the two products being the complement of 

1 Proceedings of the Institute of Mechanical Engineers, 1884. 



AMERICAN LOCOMOTIVE PRACTICE 185 

each other. This fact is quite consistent with approximately 
equal proportions of carbon and hydrogen, and Table XII 
is given to illustrate this. The following is an abstract of 
Urquhart's paper — 

" Comparing naphtha refuse and anthracite, the former has a 
theoretical evaporative power of 16-2 pounds of water per 
pound of fuel, and the latter of 12-2 pounds at a pressure of 
8 atm. or 120 pounds per square inch ; hence petroleum has, 
weight for weight, 33 per cent, higher evaporative value than 
anthracite. In locomotive practice a mean evaporation of 
from 7 pounds to 7 J pounds of water per pound of anthracite 
is generally obtained, thus giving about 60 per cent, of effi- 
ciency, while 40 per cent, of the heating power is lost. But 
with petroleum an evaporation of 12-25 pounds is practically 
obtained, giving 

9 = 75 per cent, efficiency. 

Thus petroleum is theoretically 33 per cent, superior to 
anthracite in evaporative power ; and its useful effect is 25 
per cent, greater, being 75 per cent, instead of 60 per cent. 
Weight for weight, the practical evaporative value of petroleum 
is at least from 

12 25 - 7-50 ao , . 12-25 - 700 

— — = 63 per cent, to =-^. = 75 per cent. 

higher than that of anthracite. 

Spray Injector. 

" Steam, not superheated, being the most convenient for 
injecting liquid fuel into the furnace, it remains to be proved 
how far superheated steam or compressed air is superior to 
saturated steam — taken from the highest point inside the 
boiler, by a special internal pipe. In using several systems 
of spray injectors, he invariably noticed the impossibility 
of preventing leakage of tubes, accumulation and inequality of 
heating of the fire-box. 

" The work of a locomotive is very different from that of a 
marine or stationary boiler, owing to the frequent changes of 
gradient on the line, and the stoppages at stations, which 
render firing with petroleum very difficult ; and were it not for 
properly arranged brickwork inside the fire-box, the spray jet 
alone would be quite inadequate. The efforts of engineers, 
have been mainly directed towards arriving at the best kind of 
spray injector for so minutely sub-dividing a jet of petroleum 



186 LIQUID FUEL AND ITS APPARATUS 

into a fine spray, by the aid of steam or compressed air, as 
to render it easy of ignition. For this object nearly all the 
known spray injectors have very long and narrow passages for 
petroleum as well as for steam ; the width of the orifice does 
not exceed from J mm. to 2 mm., or 002 in. to 008 in., and in 
many instances is capable of adjustment. 

" With such narrow orifices any small solid particles which 
may find their way into the spray injector along with the petro- 
leum will foul the nozzle and check the fire. Hence in many 
steamboats on the Caspian Sea, although a single spray injector 
suffices for one furnace, two are used, in order that when one 
gets fouled the other may still work ; but, of course, the fouled 
orifices require incessant cleaning out. 

" Locomotives. — In arranging a locomotive for burning petro- 
leum, several details require to be added in order to render the 
application convenient. For getting up steam, to begin with, 
a gas pipe of 1 in. internal diameter is fixed along the outside 
of the boiler, and at about the middle of its length it is fitted 
with a three-way cock, having a screw nipple and cap. The 
front end of the longitudinal pipe is connected to the blower 
in the chimney, and the back end is attached to the spray 
injector. Then by connecting to the nipple a pipe from a 
shunting locomotive under steam, the spray jet is immediately 
started by the borrowed steam, by which at the same time a 
draught is also maintained in the chimney. In a fully equipped 
engine-shed the steam would be obtained from a fixed boiler 
conveniently placed and specially arranged for the purpose. 
Steam can be raised from cold water to 3 atm. pressure in 
twenty minutes. Auxiliary steam is then dispensed with, and 
the spray is worked by steam from its own boiler ; a pressure 
of 8 atm. is then obtained in from 50 to 55 minutes from the 
time the spray jet was first started. In daily practice, when 
it is only necessary to raise steam in boilers already full of hot 
water, the full pressure of 7 to 8 atm. is obtained in twenty 
to twenty-five minutes. While experimenting with liquid 
fuel for locomotives, a separate tank was placed on the tender 
for carrying the petroleum, having a capacity of about 3 tons. 
But a separate tank on the tender, even though fixed in place, 
would be a source of danger from the possibility of its moving 
forwards in case of collision. As soon as petroleum firing was 
permanently introduced, the tank for fuel was placed in the 
coal spaces of the tender between the two side compartments 
of the water tank. For a six-wheeled locomotive the capacity 
of the tank is 3| tons of oil, a quantity sufficient for 250 miles, 



AMERICAN LOCOMOTIVE PRACTICE 187 

with a train of 480 tons gross, exclusive of engine and tender. 
In charging the tank with petroleum, it is important to have 
strainers of wire cloth in the manhole of two different meshes, 
the outer one having openings of, say, J in., the inner say of 
J in. [In later English practice the strainer is much finer than 
this. — Author.] These strainers are occasionally taken out 
and cleaned. If care be taken to prevent solid particles from 
entering with the petroleum, no fouling of the spray injector 
is likely to occur, and if an obstruction should arise, the ob- 
stacle, being of small size, can be blown through by screwing 
back the steam cone in the spray injector far enough to let 
the solid particles pass and be blown into the fire-box. This 
expedient is easily resorted to even when running and no more 
inconvenience arises than an extra puff of dense smoke for a 
moment, in consequence of the admission of too much fuel. 
Besides the two strainers in the manhole of the petroleum 
tank on the tender, there should be another strainer at the 
outlet valve inside the tank, having a mesh of J in. holes, 

" In lighting up, precise rules must be followed to prevent 
explosion of any gas accumulated in the fire-box. First clear 
the spray nozzle of water by letting a small quantity of steam 
brow through, with the ash-pan doors open ; at the same time 
start the blower in the chimney for a few seconds, and any gas 
will immediately be drawn up the chimney. Next, place on the 
bottom of the combustion chamber a piece of cotton waste 
or shavings, saturated with petroleum and burning with a 
flame. Then open first the steam valve of the spray injector, 
and next the petroleum valve gently ; the first spray of oil 
coming on the flaming waste ignites without any explosion 
whatever, after which the fuel can be increased at pleasure. 
By looking at the top of the chimney, the supply of petroleum 
can be regulated by observing the smoke. The general rule is to 
allew a light blue smoke to escape, showing that neither too much 
air is being admitted nor too little. The combustion is under 
the control of the driver, and the regulation can be effected 
so as to prevent smoke altogether. While running the driver 
and fireman should act together, the latter having at his side 
of the engine the four handles for regulating the fire, namely, 
the steam wheel and the petroleum wheel for the injector, 
and the two ash-pan door handles in which are notches for 
regulating the air admission. Each alteration in the position 
of the reversing lever or screw, as well as in the degree of open- 
ing of the steam regulator or the blast pipe, requires a corres- 
ponding alteration of the fire. Generally the driver passes the 
word when he intends shutting off steam, so that the alteration 



188 LIQUID FUEL AND ITS APPARATUS 



in the firing can be effected before the steam is actually shut off ; 
and in this way the regulation of the fire and that of the steam 
are virtually done together. This care is necessary to prevent 
smoke and waste of fuel. When, for instance, a train arrives 
at the top of a bank which it has to go down with the brakes on, 
exactly at the moment of the driver shutting off steam and 
shifting the reversing lever into full forward gear the petro- 
leum and the steam are shut off from the spray injector, the 
ash-pan doors are closed, and if the incline be a long one, the 
revolving iron damper over the chimney top is moved into 
position, closing the chimney, though not hermetically. The 

accumulated heat is 
thereby retained in 
the fire-box ; and the 
steam even rises in 
pressure, from the 
action of the accumu- 
lated heat alone. As 
soon as the train 
reaches the bottom 
of the incline and 
steam is again re- 
quired, the first thing 
done is to uncover 
the chimney top ; 
then the steam is 
turned on to the 
spray injector, and 
next a small quan- 
tity of petroleum is 
admitted, but with- 
out opening the ash- 
pan doors, a small 
fire being rendered 
around the injector, as 
The spray, 




Fig. 38. Goods Locomotive, Urquhart 
System, Grazi-Tsaritzin Railway. 



possible by the entrance of air 
well as by leakage past the ash-pan doors, 
immediately on coming in contact with the hot chamber, 
ignites without audible explosion ; and the ash-pan doors are 
finally opened, when considerable power is required, or when 
the air otherwise admitted is not sufficient to support complete 
combustion. By looking at the fire through the sight hole, 
it can always be seen at night whether the fire is white or 
dusky ; in fact, with altogether inexperienced men, it was 
found that after a few trips they could become quite expert in 
firing with petroleum. The better men burn less fuel than 



AMERICAN LOCOMOTIVE PRACTICE 189 

others, simply by greater care in attending to the essential 
points. 

" Several points have arisen which must be dealt with to 
ensure success. The distance ring between the plates around 
the firing door is apt to leak in consequence of the intense heat 
and the absence of water circulation ; it is therefore protected 
by having the brick arch built up against it, or, better still, a 
flanged joint is substituted. This arrangement occasions no 
trouble whatever." 

The fire-box arrangement of the goods locomotive is shown 
in Fig. 38. The sprayer points downwards upon the hearth 
which is built in the ash-pan, and continuous with the 
bridge and arch. A block of brickwork is placed under 
the sprayer, and below that is a passage for air. The bridge 
is continued up to the crown of the box, but is perforated 
and the whole of the front tube plate is exposed to heat. The 
fire-box surface is 82 sq. ft. Total heating surface, 1,248 sq. 
ft. " Grate " area, 17 sq. ft. Weight, 36 tons in running 
order. Pressure, 120 to 135 pounds. 151 tubes 13 ft. 10 in. 
long x 2 in. outside diameter. 

Fig. 39 shows the petroleum tank in the tender, the heating 
coil C surrounding the filter whence the oil is drawn through a 
cock V and pipe P to the sprayer. Steam goes by way of the 
pipe S and escapes at T. W is the collector for water. 

Fig. 40 shows another furnace arrangement, in which the 
brickwork of the fire-box sides is made cellular, and air is 
admitted also below the sides by lateral openings K with 
regulating dampers. The fire-doors are quite blocked, and only 
a sight hole left at H. 

A later design is that of Fig. 41. This includes a lined ash- 
pan, bridge and over-arch, with a passage through it for air 
admitted by the forward ash-pan damper. Lateral arches are 
provided in order that the side sheets of the fire-box may be 
exposed to the heated gases. No part of the fire-box is actually 
in touch with the fire-brick, yet the burning oil is completely 
enclosed with a brick oven. As very usual in Continental 
practice, the engines had the closing cap to the chimney top. 
This is used to retain heat in the fire-box at times of standing, 
and should be a most effectual damper. With liquid fuel 
employed without solid fuel, the closing of the chimney is very 
efficient in retaining the heat of the brickwork, and this damper 
is used when running down hill, and, on again turning the oil 
spray into the furnace it is at once ignited by the hot brickwork. 
There is a pointer and scale on the spindle of the regulating 




d5 






190 



AMERICAN LOCOMOTIVE PRACTICE 



191 



valve D for use by night. The Auther has noticed on the 
Great Eastern Railway, that when apparently quite dark, the 
chimney top can be seen sufficiently to judge of smoke. 

The injector is shown in Fig. 42. It consists of a central 
steam jet, an annular passage for oil and an outer annulus 
for air. The steam jet is regulated by sere wins; the steam cone 




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to and fro by a worm and wheel on the regulating handle 
and spindle. The steam cone can readily be removed for 
clearing purposes, or the back plug can be taken out while 
the sprayer is at work, with little delay, a wire being intro- 
duced to remove any possible obstruction that the steam will 
not discharge. 




o / 3. y + r>Fu* 



193 



Thtn of | C% j Spray Injector. 




3 4- 5 6 7 * 

i - i ' ' I 1- 



10 II 11 b, 3 



Fig. 42. Atomizer. Urquhart's. 

193 n 



194 



LIQUID FUEL AND ITS APPARATUS 



Economies of 45 and 57 per cent, over anthracite and bitum- 
inous coal changed to 57 and 67 hi an engine arranged to warm 
the air slightly, and Urquhart thought the air ought to be 
heated, and this is well established as good practice. 

The fuel consumption of all kinds appears high, but this is 
attributable to long waiting on a single line and to the weight 
of trains, often as much as 720 tons, and the exposed country, 
with strong side winds. 

ConsivnvpUxrrh of FweL per Trctirv - Mile 
Coat - FujZ lines Petroleum. : - Dotted lines 



100 




A (roods Engme, 8 wheels ampled. Goods Train 

BB , . 6 . 

C Mjced . 4* 4 Mioced 

DI) , 4 „ 'Passenge* . 

Fig. 43. Locomotive Performances with Coal and Oil Fuel. 
Urquhart's System, Grazi-Tsaritzin Railway. 



Considerable space has been given to this system and to the 
figures and drawings, because though now old and dating back 
nearly 30 years, Urquhart had the correct principles of combus- 
tion fully before him, and laid out his arrangements with a 
perfection that cannot be much improved upon to-day. He 
saw clearly what was necessary, and this may be summed up 
in the words, Atomizing, Air and Temperature. Hence the 
success he attained, and the correctness of his arrangements 
and conclusions. 

In Fig. 43 are curves showing the consumption of oil and 
coal, and in Table XIII are some useful data on specific gravity. 



CHAPTER XII 

AMERICAN STATIONARY PRACTICE 

The Billow System. 

THE fuel oil appliances of the National Supply Company of 
Chicago consist of pumps and atomizers. 

Atomizers are actuated in one or a combination of the follow- 
ing ways — by steam, by air supplied by an air compressor, or 
from a positive blast blower or fan. 

An oil burner becomes more efficient and approaches nearer 
to perfection which will pulverize the greatest amount of oil 
with the least energy, and will vaporize oil at the point of 
3xpansion of the agent used for that purpose. 

Atomizers are constructed with various shaped openings — 
annular, flaring, slotted, semicircular or fan-shaped, producing 
either a long, round, or a broad spreading flame. 

Annular openings are said to be more economical in steam or 
air than other forms, as a more intimate association of the oil 
and the vaporizing agent is afforded. 

By actual experiment atomizers consume from 3 to 15 per 
cent, of the entire product of the boiler in vaporizing sufficient 
oil to develop the capacity of the boiler. 

The number of atomizers required for each boiler or furnace 
is directly proportionate to its size. Of atomizing agents steam 
is considered the best for boilers, air from a positive blast 
blower for furnaces where heat of medium intensity is required, 
and air from a compressor for small furnaces. These are 
opinions not held universally as regards boiler furnaces. 

The Billow Atomizer (Fig. 44) is designed to vaporize the 
greatest amount of oil with the least expenditure of energy, 
is automatic in its operation within a 5 per cent, steam variation. 
It is of a form which it is claimed precludes the possibility of 
choking, clogging, dripping or the wasteful use of steam, air or 
oil. It is self contained. The fuel and the atomizing agent 
are controlled within the burner. It has ground joint union 
pipe connexions placed on an axis transverse to the body, a 



196 



LIQUID FUEL AND ITS APPARATUS 



feature which permits the flame to be directed as desired. It 
has a wide range in adjustment, and will vaporize a few drops 
of oil per minute or many gallons per hour. It is constructed 
with various shaped nozzles or outlets of the retort type, 
when desired, but these are not recommended on account of 
their wasteful steam or air consumption. Only in special 



°u 



Scale 




OIL BURNER 

CL/JSS DC 



Fig. 44. Atomizer. Billow System. 

instances should atomizers other than those with annular 
openings be employed. 



Fuel Oil Pumping Systems. 

In America oil is pumped to the atomizer, not gravitated. 
The system for oil handling and control between the storage 



AMERICAN STATIONARY PRACTICE 197 

tank and the atomizers is an important factor. This system 
is designed to heat the oil, free it from mechanical impurities, 
and deliver it to the atomizer at a constant pressure and 
temperature under the control of the operator. The amount of 
oil necessary for feeding the atomizers should be automatically 
controlled, and the system sufficiently flexible to pump the 
oil to one atomizer or any number within its capacity without 
useless expenditure. It should handle all grades of oil fuel 
equally well. 

Residuum, or manufactured fuel oil, often contains particles 
of coke and sand. All grades may have dirt and other matter 
which disturb the adjustment of the atomizers at the furnace 
door, necessitating their frequent cleansing. These impurities 
clog the feed lines, necessitating frequent blowing-out. An 
oil pumping system provides against this by filtering out these 
accumulations and cleaning the filtering medium without 
disturbing the continued performance of the pump. 

Feeding the oil at a temperature nearly approaching the 
point of distillation ensures speedy vaporization, with a result- 
ant flame soft and diffusing, and not sharply impinging upon 
the boiler surfaces. The pumping system is designed to 
give the desired heat, and is provided with automatic govern- 
ing valves to ensure uniform delivery. 

The National Supply Co. have designed oil fuel pumping 
systems for modern fuel oil non-gravity equipments. They 
are compact, and so dripped and drained that no oil can reach 
the floor. 

Any oil fuel produces the best results when heated to a tem- 
perature just under its distilling point, and oil is atomized 
with less energy when heated to such a temperature and 
delivered under constant pressure. 

When air is used as an atomizing agent, carbonization is not 
liable to occur at the outlet of the burner in the furnace because 
the oil is passed through water heated with exhaust steam in 
the receiver, and minute quantities of water vapour are carried 
over with the oil and prevent carbonizing. 



Double Pumping System. 

These oil pumping systems (Fig. 45) consist generally of two 
duplex steam pumps, specially brass fitted for oil, and of a 
cast-iron receiver, tested to two hundred pounds pressure, 
mounted on a cast-iron drip pan and base frame upon which the 
mechanism is fastened. A partition divides the receiver into 
two chambers. Projecting into the rear chamber and screwed 



198 



LIQUID FUEL AND ITS APPAEATUS 



to the partition are tubes with fine gauze heads, accessible 
through the rear head of the receiver. These heads act as a 
straining medium, and there is a blow-off pipe and valve for 
removing deposit. 




Fig. 45. Double Pumping System. Capacity, 1 to 5,000 Boiler H.P. 



The forward chamber is usually two-thirds full of water, 
and contains a coil of pipe through which flows live steam or 
exhaust steam from the pump. The coil has controlling valves, 
permitting the use of steam from either of these sources or both 
at the same time. 



AMERICAN STATIONARY PRACTICE 199 

One pump is in reserve against contingencies or accident to 
the other. 

The apparatus is provided with a pump governor, or regu- 
lator, actuated by the pressure in the receiver to maintain a 
constant pressure on the oil in the receiver ; an adjustable relief 
valve placed between the suction and the delivery side of the 
pump through which all oil in excess of the requirements of the 




Fig. 46. Compound Tuyere for Air Admission. 

atomizer may pass in case of accident to the governor ; a 
thermometer, steam, oil, pressure, and automatically closing 
sight gauge. 

The oil is discharged through the force chamber of the pump 
into the forward chamber. The oil flowing through the hot 
water becomes heated and passes out through an inner tube 
to the point of consumption. 

These pumping systems are made up to sizes of ten to 
eighteen thousand boiler horse-power. 



200 LIQUID FUEL AND ITS APPARATUS 



Thus No. 5 Double, employing two 5j-in. by 3j-in. by 5-in. 
duplex steam pumps, has a capacity of five to fifteen thousand 
boiler horse-power, or twenty to forty gallons per minute. 

In attaching fuel oil atomizers to furnace or boiler fronts it 
is sometimes necessary to admit all the air for vaporization 

and combustion at 
the atomizer, for the 
reason that at no 
other point can a 
sufficient amount of 
air be induced into 
the furnace to com- 
plete combust ion, 
owing to conditions of 
draught or construc- 
tion. The device of 
Fig. 46 answers this 
purpose, by providing 
the air for combustion 
irrespective of the 
atomizing agent used. 
This air for combus- 
tion is intimately 
mixed with the oil at 
the point of admission 
into the furnace. It 
is intended for boilers 
where oil is burned 
as an auxiliary to 
some other form of 
fuel, making it im- 
possible to dispense 
with the grate bars, 
and is therefore use- 
ful in connexion with 
the burning of 
bagasse, sawdust and 
material of like char- 
acter. It is also the 
form used aboard 
vessels that employ 
water tube boilers. 
The tuyere or air regulator attached is shown enlarged in 
Fig. 47, the outer part being revolvable so as to close the air slots 
and regulate the air admitted round the atomizer. These 




Fig. 47. Am Regulator, Atomizer and 
Tuyere Block for Furnace Front. 



AMERICAN STATIONARY PRACTICE 



201 



appliances are the designs of the National Supply Co., of 
Chicago, as also is the arrangement, Fig. 49, of atomizer 
tuyere, casting, and internal block of fire-brick which is 
intended to be placed in a furnace wall or in the fire-front of 
a boiler. The fire-brick has a trumpet-shaped hole through 
it, and the nozzle of the atomizer enters a short distance 
only, so that the initial flame is contained within the body 
of the block. This block has a good effect in effecting perfect 
combustion. 

An example of the National Co.'s system is the fuel oilplant 
of the Union Loop, Chicago, Illinois. This plant consists of a 
system for the unloading, storing, circulating, controlling 
and firing of fuel oil, after designs prepared by C. 0. and E. E. 
Billow. 



-~Kb 








Fig. 48. Special Tank Car 3-inch Hose Connexion. 



The plant includes three steel storage tanks, 16, 10, and 8 
feet in diameter, and 20 feet high, of a combined capacity 
of 1,764 bbls., of 42 U.S. gallons each (35 imp. gals.). 

Fuel oil is received in tank wagons, and transferred to the 
tanks by two duplex pumps, having 6-in. steam and 7|-in. oil 
cylinders, and a 6-in. stroke. These pumps have 6-in. suction 
and 5-in. discharge. 

Provision is made for unloading four 30 bbl. tank wagons 
simultaneously. These tank wagons are attached to oil 
hydrants, by steel band lined oil unloading hose. 

The storage tanks are provided with flanges for pipe con- 
nexions, a 16-in. screw top manhole and cover on the roof, and 
an 18-in. on the side near the bottom of the tank, floats and 
level indicators by finger boards in the tank room and mercury 
columns in the basement. 

From the storage, the oil is conveyed to two 4-in. stand pipes, 
70 ft. in height, joined by a header near the top, by means of a 



202 LIQUID FUEL AND ITS APPARATUS 

duplex pump, having 3|-in. steam cylinder, 4£-in. oil cylinder, 
and a 5-in. stroke. This pump has a 3-in. suction and a 21- 
inch discharge. 

From the stand pipe header the oil is conveyed to the oil 
atomizer loop, by two No. 5 oil heating and circulating systems, 
set upon the boiler room floor. These automatically maintain 
a uniform pressure and temperature, and a constant flow of oil. 
They consist of a battery of duplex pumps with 5j-in. packed 
pistons having 3j-in. oil cylinders, a 5-in. stroke, a 2|-in. 
suction and a 2-in. discharge. Each pump has a copper air 





Fig. 49. 

chamber and is mounted on a cast-iron base and drip pan, to 
dispose of all leakage of glands. The base is attached to a 
cast-iron frame, supporting one combined steel receiver, heater 
and condenser, 24 inches in diameter, and 36 inches high, sur- 
mounted by the 7-in. copper air chamber 24 inches high. The 
receiver has two diaphragms riveted to its shell, and expanded 
full of tubes (125 1-in. boiler tubes, having their ends caulked 
and beaded), around which passes the exhaust from the pumps. 
The receiver also has provision for the introduction of water, 
through which the fuel oil flows, under a high pressure, for the 
purpose of breaking it up, in order that all foreign substances 
may be precipitated ; the oil passing through the heated tubes 
is thoroughly cleansed, and deposits water and settlings. 



AMERICAN STATIONARY PRACTICE 203 

The drips from the pumps receiver, drip pans, and exhaust 
have catch basin connexions. 

The whole system is as nearly automatic in its action as is 
desirable, and is duplicate throughout. 

Each system is capable of delivering sufficient fuel oil to 
develop 15,000 horse-power, and occupies a floor space of 30 
sq. ft., and is 8 ft. in height. 

Four atomizers are placed in the combustion chamber of 
each boiler, or a total of sixty-four oil burners compose the 
installation. These oil burners receive their oil from a loop, 
beneath the boiler room floor, which is divided by valves into 
five distinct headers. 

The furnaces are erected upon the grate bars of an Acme 
stoker, and consist of a series of fire-brick flues for heating 
and circulating the incoming air, chequer work for distributing 
flame, and baffle walls for directing same. 

Oil at the same uniform pressure and temperature can be 
delivered to a single burner or to the entire sixty-four. 



Furnace Construction. 

" Too often it happens that complete combustion is impaired 
not from the lack of air, but on account of the method of its 
introduction into the furnace, often from such points as to 
render it ineffective, producing losses as great as 50 per cent. 
For economic reasons no more air should be supplied than is 
necessary. 

"During the early stages of combustion of any fuel the gases 
of a highly volatile nature distil at a low temperature, rise 
rapidly, hug the boiler, enter the tubes or flues and pass away 
unconsumed. The combustion chamber should therefore be 
arranged with fire-brick, so that the incoming air may be heated 
to the required temperature, the flames retarded, diffused, 
and distributed, and the velocity impeded. There will be no 
concentration or localization, and the danger of blistering or 
burning is avoided. 

"The furnace construction varies according to the type of 
boiler or furnace. The question may be asked, ' Will an 
apparatus work if no change is made in the combustion chamber 
or furnace of a boiler other than that of covering the grate 
bars ? ' A furnace so arranged will not average so high 
economical results as when constructed for diffusing the heat 
and retarding the flow of the gases. Fuel oil appliances can 
only vaporize the oil ; in the furnace it is consumed. There- 
fore the statement is not unreasonable that a scientifically 



204 LIQUID FUEL AND ITS APPARATUS 

arranged combustion chamber with a shovel to feed the oil is 
preferable to a poorly constructed furnace to which is attached 
the highest type of atomizing device. 

Operating a Fuel Oil Plant. 

" The results to be secured from a properly designed fuel oil 
plant depend largely upon the amount of intelligence exercised 
in its manipulation. All the mechanism that can be supplied, 
outside of the furnace, is designed to perform the single function 
of delivering the oil to the furnace in a finely divided, nebulized 
condition with as little cost to the operator as possible, and to 
give insurance against accidents or possible shut-downs, with 
ease and facility in manipulation. Other economical results 
depend wholly upon the draught. This should be regulated by 
the ash-pit doors, or other proper means. The flame may be 
increased or diminished at will by the simple opening or closing 
of a valve, but it is only by experiment or long-continued con- 
tact with fuel oil that the oil, the atomizing agent, and the air 
necessary for combustion will be properly combined and the 
beneficial results of this combination be obtained. The operator 
should continue the opening and closing of the ash-pit doors, 
or the manipulation of the damper and the increasing or 
diminishing of the flame until he can produce a fire large or 
small, without the least indication of smoke. When this con- 
dition is attained he will have no more occasion for handling any 
of the apparatus provided the elements of combustion are 
perfectly balanced. 

" The gases should not pass from the furnace at two high a 
temperature. This can be controlled and regulated largely 
by the damper. A clear flame consumes less oil than a smoky 
flame, and has greater efficiency. Smoke is evidence of imper- 
fect combustion, but the absence of smoke does not necessarily 
prove that perfect combustion is being attained. Too much 
steam produces a light grey vapour ; too little, a smoky flame ; 
too great a draught, an intensely vibrating flame accompanied 
with a roaring noise ; too little draught produces a dull red 
smoky flame. When the elements are properly united the 
result is a reddish orange flame. 

" The temperature of the escaping gases from a boiler will 
increase as the excess of air becomes greater, provided the same 
amount of fuel is being burned. This is because the furnace 
temperature is less, owing to the greater amount of air present 
which results in a less rapid transfer of the heat to the boiler 
and consequently allows more heat to escape to the chimney. 




205 



206 



LIQUID FUEL AND ITS APPARATUS 



" On the other hand, with a uniform excess of air, if more fuel 
is burned, the temperature of the escaping gases will increase, 
owing to the heat produced being greater in proportion to the 
absorbing capacity of the boiler." 

It is only through close application that the theory of oil 
burning can be fully understood and mastered and as high an 
efficiency as 80 per cent, of the theoretical value of the fuel 
transmitted from the furnace to the boiler. Mr. C. 0. Billow 
has designed furnaces for many types of boilers. Fig. 50 is the 
ordinary American under-fired tubular boiler with the bars 
replaced by a fire-brick air casing, through which air flows to 




Fig. 51. Water-Tube Boiler. Billow System. 



the furnace through the " ash-pit " door and comes up under 
the atomized jet. The furnace widens out laterally from 
front to rear, the atomizer being placed at the narrow end of 
this brick furnace. The grate bars are ten inches lower than 
usual, and the air casing of brick occupies this ten-inch space. 
The ash-pit doors regulate the air admission. The atomized 
oil is directed upon the chequer work brick bridge, which 
breaks up and diffuses the flame throughout the furnace and 
directs it upon the boiler. A hanging bridge is placed at the 
extreme end of the combustion chamber. If too little air has 
been admitted at the front, a further supply is let in through 
this rear bridge, which also serves further to retard the flow 



AMEKICAN STATIONARY PRACTICE 



207 



of the hot gases. Either steam or air may be used as the 
atomizing agent, and though air is the more efficient, the cost 
of the air compressor detracts from its advantage, but a good 
compressor saves steam. Mr. Billow considers that steam 
atomizing should be done with 3-3 per cent, of the total steam ; 
that a positive air blast blower will only use 1-36 per cent, of the 
boiler output, but when air is compressed above 30 pounds 
absolute, it costs 6 per cent, with ordinary compressors. Hence 
the importance of good compressors. The same system is 
carried out in the ordinary water- tube boiler (Fig. 51). This 
furnace is applicable to the many forms of water-tube boiler. 
The same grate cover of fire-brick is employed, but the bars 



OIL PIPE ^2,;' AIR I 

■■/>' NAVY GLOBE VALVE 



2'V HANDY GATE VALVE 




5x7 AIR PORT- 



TYPICAL MOUNTING 
or 

CLASS *«LM" BILLOW ATOMIZER 9" 

Fi 2 . 51a. 



are lowered considerably to provide room for the concave 
bridge, which is also split to admit air. The burner points 
somewhat down so as to strike on the brick floor at about half 
length, the flames curving round the bridge hollow. 

It may be added that for English practice the containers 
of oil pumping systems, if employed in preference to gravity 
feeds, of Fig. 45 type should be of boiler plate and not of cast- 
iron — a material, the use of which for pressure work, and 
especially for pressure work with liquid fuel, is considered 
indefensible, and would probably not be passed as safe by 
the English boiler insurance companies. Fig. 51a shows a 
typical boiler mounting on the Billow system. 



CHAPTER XIII 

ENGLISH STATIONARY PRACTICE WITH LIQUID FUEL 

The Kermode System. 

IN this system air at low pressure is the atomizing agent, 
the air being heated in a thick retort pipe, which is 
carried round the furnace or uptake. 

Oil gravitates from an overhead tank, as very usual in 
marine work. It flows thence by a lj-in. pipe to the furnace 
front and separates to the two burners by equal branching 
pipes. Where two burners are supplied off one pipe the 
branches to each must be symmetrically arranged in order 
that equal supplies of oil may reach each burner. 

The illustrations represent one form of the furnace arranged 
by the Wallsend Slipway Co. for this system, the lower 
part of the marine furnace being filled with special fire-brick 
blocks through which air enters the furnace beneath the flame. 
These blocks are covered with asbestos lumps similar to the 
ordinary grate of Fig. 53, which shows an alternative arrange- 
ment including also an oil heating pipe in the furnace in addition 
to the air heating pipe. 

The accompanying table of tests and copy of analysis of 
Borneo oil are given from results of trials at the Wallsend 
Company's Works — 

Copy of Analysis by Dr. George Tate, F.I.C,, F.G.S., 
November 9, 1899. 



Sample. 



Astatki. 



Borneo 

Crude Oil 

as received. 



Borneo 

Crude Oil 

dried. 



Water 

Carbon 

Hydrogen 

Oxygen and undetermined elements 

Total 

Calorific power in B.Th.U. . 
Equivalent evaporative power 



p. C 

trace 

79-92 

1200 

8-08 



100-00 

18-434 
19-0 lb. 



p. c 
11-75 

73-60 
9-08 
5-57 



100-000 

15-894 
16-4 lb. 



p. c. 

83-40 

10-29 

6-31 



100 00 

18010 
18-6 lb. 



208 






m m 




\±m 




210 



ENGLISH STATIONARY PRACTICE 



211 



liquid Fuel 
' Pipe 




Fig. 53. Liquid Fuel Furnace. Kermode's System. Alternative 

Arrangement. 



Date of Trial. 



Duration of trial 
Class of oil used 



Mean pressure on boiler, lb. 
Total lb. of water evaporated 
Pounds evaporated per hour 
Pounds of water per pound of oil 
Ditto from and at 212°F. . 
Mean temperature of feed water 

deg. Fahr 

Temperature of oil in measuring 

tank, deg. Fah. 
Total gallons of oil consumed 

,, pounds of oil consumed 
Gallons consumed in 1 hour 
Pounds consumed in 1 hour 
Pressure on oil at burner pound 
Specific gravity of oil 
Temperature of uptake deg. F. 
Smoke at funnel top . 

Air pressure in burner, pounds 
Revolutions of blowing engine . 
Pounds of oil per sq. ft. of grate 
Pounds of water per sq. ft. of 
heating surface .... 



Sept. 6, 


Sept. 14, 


1899. 


1899. 


3 hours 


4 hours 


Borneo 


Borneo 


crude 


crude 


111 


110-5 


24,161 


35,323 


8053-7 


8830-75 


111 


10-9 


12-9 


12-75 


89° 


89° 


68° 


68° 


225-3 


337 


2174 


3244 


751 


84-2 


724-7 


811 


4-3 


4-3 


•965 


•965 


650° 


665° 


Light 


Light 


brown 


brown 


3-2 


3-2 


310 


350 


181 


20-3 


4-75 


5-5 



Sept 19, 1899. 



2 hours 
Borneo crude 



First hour 
109-8 

9362-5 

9362-5 
10-93 
12-85 

83° 

67° 
88-8 
856-5 
88-8 
856-5 
4-3 
•965 
720° 



Second hour 

110-4 

9511 

9511 
10-92 
12-84 

83° 



67° 
90-2 
870-3 
90-2 
870-3 
4-3 
•965 
720° 
Light brown 



3 

320 
21-5 

5-5 



7 -5 per cent, of water in the oil is allowed for in the above results. 
This seems rather excessive, but probably explains the results. 



212 LIQUID FUEL AND ITS APPARATUS 

The boiler had the following dimensions : — 

Mean diameter 12 ft. 6 ins. 

Mean length lift. 

Two furnaces 3 ft. 7 ins. inside diameter. 

262 tubes 2| ins. external diameter, 

8 feet between tube plates 

Heating surface of tubes .... 1,372 sq. ft. 

Furnaces 123 „ 

Combustion chambers 125 ,, 

Tube plates 75 „ 

Total 1,695 

Grate area of one surface. ... 20 „ 

Diameter of chimney 5 ft. 

Height from bars 55 ,, 

The burners are arranged so as to be readily swung back 
when coal firing is to be resumed, and there is very little change 
to the furnace in the system of Fig. 53. Probably the light 
smoke which is made might be reduced by the use of somewhat 
more fire-brick in the furnace or combustion chamber. 

Tests made at Birkenhead are said to have shown an evapora- 
tion as high as 15-5 pounds from and at 212°F. per pound of 
Russian astatki and without smoke. Borneo oil is credited by 
Dr. Tate with less hydrogen than usually is found in petroleum 
fuels, the average formula apparently being C 7 H 10 . The latest 
burner for this system is described under the head of atomizers, 
Fig. 68. 

The remarkable thing in this system is the satisfactory results 
obtained with only 3 pounds of air pressure, but it must be noted 
that this air is highly heated. The above trials, made many 
years ago, show what improvements have since been made for 
to-day (1911). 

The following figures show the results which can be obtained 
on a steam boiler fitted with any one of the three systems 
of atomization used in the Kermode system. 

Oil fuel, which has a theoretical calorific value of 19,320 
British thermal units per pound, is capable of evaporating 20 
lb. of water from and at 212° F. (theoretically) for every pound 
of oil consumed, and if the air-jet system is used, from 15-6 
to 16-6 lb. of water can be evaporated per pound of oil consumed 
under practical working conditions. That is to say, from 78 
per cent, to 83 per cent, of the theoretical calorific value of the 
oil is recovered for useful work. 

The pressure- jet system will recover from 70 per cent, to 75 
per cent, of the theoretical calorific value of the oil fuel used in 
actual practice. That is to say, with oil fuel of 19,320 B.Th.U.'s 



S-— 




213 



214 LIQUID FUEL AND ITS APPARATUS 

per lb., the evaporation per pound of oil consumed would be 
from 14 to 15 lb. of water per lb. of oil consumed. 

The steam- jet system will recover from 68 per cent, to 74 
per cent, of the calorific value of the fuel used, or a pound of 
oil foul will evaporate from 13*6 to 14 8 lb. of water. 

For dealing with the by-product (tar) from the Mond Gas 
power plant, the Kermode system converts a hitherto useless 
refuse to liquid fuel, and by this means an enormous saving is 
effected in the fuel bill of Mond Gas plants. 

The Kermode system embraces all three methods of atomiza- 
tion by air, by steam and by oil pressure, without other agency, 
the oil spraying itself by its own energy. An example of each 
type of sprayer will be found in the chapter on atomization. 

In Fig. 54 is shown a recent Kermode furnace as arranged 
under a Babcock boiler, on a test of which 13-32 lb. of water is 
stated to have been evaporated at 1001b. pressure from feed at 
64-4°F. per lb. of oil, the efficiency being 79-65 per cent. 

The burners themselves are shown at A, the air pipes at B, 
the oil-pipes at C, the oil-main at D and E, the air-mains at 
G, from which the branch-pipes A go to the burners, and the 
air-compressor at M, from which the air passes along the pipe 
to the heater K. An air by-pass valve is shown at N, and air- 
pipes 0, 0, which lead to the flue and discharge the surplus air 
when required. The results have quite come up to expectation, 
for the evaporation from and at 212°F. has proved to be 
15-91 lb. of water per pound of fuel, although the oil was not of 
a very high calorific value. 

During test mentioned the water evaporated per hour was 
at the rate of 1362*5 kilogrammes (3,004 lb.) per hour. The 
pressure of the air supplied to the burners was 0-7 lb. per 
square inch, with very slight variations. The temperature 
of the feed- water was 64 4°F., and that of the liquid fuel 
69-8°F. The amount of oil consumed during the eight hours' 
test was 1,801 lb., and the total amount of water evaporated 
was 23,980 lb. The Kermode system is applied equally to 
land or marine work, and to fire engines and small work, and 
any liquid fuel is utilized, notably the tar of the Mond Gas 
producer. 

Numerous large and small vessels of the Navy have been 
fitted with this system. 



The Hydr oleum System. 

In this system great stress is laid upon the spraying of the 
oil through a comparatively restricted area or passage upon a 



ENGLISH STATIONARY PRACTICE 



215 




Fig. 55. Water Tube Boiler with Hydroleum Liquid Fuel System. 

dash-brick, which, it is claimed, becomes highly heated and 
vaporizes the spray. This is shown in Fig. 55. 

Tested with water gas tar at the works of Messrs. Muirhead & 
Co., Elmer's End, Kent, the following results were obtained : — 



Date 

Duration of test .... 
Mean temperature of feed water 
Mean pressure on boiler . 
Pounds of water evaporated . 
„ ,, consumed . 

Pounds of water evaporated per lb 
from and at 212°F. . . . 

Price of tar 

Price of coke 

N.B. — In making the test the tar was taken as received, no 
deduction being made for any water it contained. 
Comparing these two tests it will be seen that : — 

To evaporate each pound of water with coke cost . 0-0172d. 
To evaporate each pound of water with water gas tar 0-0075d. 



Oil. 






Coke. 


Aug. 14, 


1901 


. May 15, 1901. 


2 hours 






9 hours 


70 Fahr. 






60 Fahr. 


90 1b. 






90 1b. 


2,400 






10,100 


211 






1,792 


13-47 






6-73 


195. Old. 


per 


ton 


= -\02d. per lb. 


21s. 8d. 


per 


ton 


= -116cL per lb. 



Saving by the system of oil firing 



0-0097d. per lb. 



216 LIQUID FUEL AND ITS APPARATUS 

The burner of this system will be found described under the 
head of atomizers, but the Hydroleum Company do not profess 
to atomize. They lay stress upon the use of a dash-brick only 
about 18 inches in front of the spray nozzle, an intense local 
heat being developed on the face of the brick. Sufficient air 
to burn the vaporized oil is induced through the openings 
provided round the spray nozzle. The sprayer is made in three 
sizes, having capacities of 1, 3, and 10 to 12 gallons of oil per 
hour, and the oil is induced to flow by the inductive action of 
the steam annulus. The feed tank is kept at a level of half an 




Fig. 56. Hydroleum Liquid Fuel System. Marine Boiler Design. 



inch below the nozzle by means of a ball float valve. From 
14-5 to 15 pounds of water are stated to be evaporated from and 
at 212°F- per pound of oil, the expense of steam being 5 per 
cent, of the evaporation. 

Though not claimed as an atomizing system, the Author 
considers that the effects of the Hydroleum burner sufficiently 
resemble atomizing for this burner to be held up as an example 
of the success of the system. 

Experience shows that for a burner capable of burning 10 



ENGLISH STATIONARY PRACTICE 217 

gallons per hour there should be an opening for air round the 
atomizer of 8" x 8", which, after deducting the cross section 
of the atomizer itself leaves sixty square inches of air opening 
for ten gallons per hour. Worked out on the basis of 15 lb. of 
air per lb. of oil fuel and 13 cubic feet per lb. the velocity per 
second of the air stream is only 13 feet. A gallon of fuel is 
taken as 10 lb., which is about correct for tar. The amount 
of fuel fed is simply regulated by the amount of steam used, 
and this draws in more or less air as required by the fuel, and 
very little regulation of the air inlets is required. A trunk 
casing is placed round each burner with opening downwards to 
reduce noise. This gives very effectual silencing. These air 
trunks may be all coupled to a common air main brought from 
outside the building. As seen by the Author, burning oil gas 
tar of Sp. Gr. 104 in a Lancashire boiler the system was smoke- 
less and very silent. The Hydroleum atomizer will be found 
described in the chapter on atomizers. 



CHAPTER XIV 

THE COMBUSTION OF VAPORIZED LIQUIDS 

The Clarkson and Capel Burner. 

IN this burner system the liquid employed is preferably the 
cheaper and commoner qualities of lamp oil. The 
burner shown (Fig. 57) is one that is fitted to floating fire 
engines. It is capable of burning 40 gallons of oil per hour 
and of developing up to 200 h.p. 

There is a gas ring to give the initial heat to vaporize the oil. 
The jets heat the coils to which the oil is fed, and the vapour 
passes from the coil to the rear of the long casting, which it 
enters through a small orifice controlled by a needle point. 
Air is admitted by a door at the back end and the vapour and 
air are thoroughly mixed in the pipe and issue round the lip 
of the mushroom valve, where ignition takes place and a large 
flaring flame of great intensity, is formed, the heat from which 
now vaporizes the oil in the coil, and the process is continuous. 
The oil is under pressure in the supply tank, the pressure being 
generated by an air pump. The pressure forces the oil through 
the system, and when, in vaporized form, this reaches the jet 
nozzle, it issues with a high velocity and induces a large flow 
of air through the valve. The needle of the jet nozzle is worked 
by the same controlling lever as regulates the cap of the burner. 
In the course of this lever, which is of compound order, is a 
maximum and minimum stop that can be regulated to prevent 
excessive opening or entire extinguishing of the flame. The 
hand wheel of the larger burner in Fig. 57 shows how this is 
effected. 

In the automobile pattern (Fig. 58) the initial heating device 
is a spirit trough containing a coil of nickel wire. Petrol or 
alcohol can be employed. The burner is placed in the cylindrical 
base of the boiler ; the case bottom is perforated for air admis- 
sion and provided with a door for inspection. 

A system of preliminary heating by means of paraffin con- 
sists of a series of asbestos wicks provided with an air 

218 





219 



220 



LIQUID FUEL AND ITS APPARATUS 



draught by a small fan and fed with a limited quantity of 

paraffin from a small cup, the main supply of oil being heated 

in the f-inch coil. 
After the cupful of 
paraffin is finished the 
flame of the main 
burner will be burning 
and will provide heat 
for further vaporiza- 
tion. 

For use in automo- 
biles, small steam-boats, 
the cheap forms of 
lamp oil are commerci- 
ally practicable, though 
they would be too ex- 
pensive for ordinary 
continuous industrial 
steam raising purposes. 
For other reasons these 
oils commend them- 
selves for the purposes 
of fire engines and fire 
floats. Here the use of 
expensive fuel is war- 
ranted by the nature of 
the service, namely, the 
extinguishment of a fire 
that may be consuming 
valuable buildings and 
their contents. Even 
the lighter petrols are 
used for steam raising 
purposes in certain 
forms of steam cars, 
the petrol being sprayed 
upon a hot cast iron 
plate through which fine 
jets of air are intro- 
duced and the heat is 
utilized to raise steam 
in coil boilers of the 

flash type into which water is injected to provide the steam 

for instant use. 

In the Clarkson system one pound of oil can be counted 




THE COMBUSTION OF VAPORIZED LIQUIDS 221 

upon to give an evaporation of 10 pounds of water from 80°C, 
to steam at 200 pounds, or an equivalent evaporation from 212° 
F. of nearly 11 pounds. The oil receptacle is usually worked 
at a pressure of 40 pounds, and the cheaper grades of Russian 
oil are perhaps the most suitable, such as Rocklight, Lustre, etc. 

As stated elsewhere, the calorific capacity of all the petroleum 
products is practically identical, the lighter oils being more 
powerful because they contain the highest percentage of hydro- 
gen, but the difference is immaterial. The evaporative effici- 
ency of the small boilers of cars and canoes, is less than that of 
large boilers simply because it is not desirable to load up a car 
with too great a weight of heating surface. 

In the starting device employed on automobile cars, a pad 
fed with a drop feed of oil is ignited by a match and gives pre- 
liminary heat to the burner. 

The combustion of petrol is a special case of vaporization 
before combustion. Petrol has such a low flash point that it 
is absorbed by air passing over it, with great avidity. 

Petrol engines are simply gas engines with electric ignition 
which use petrolized air. The petrol is fed into a vessel called 
the carburettor in small quantities by the action of a float, and 
it is taken up by a stream of air which is drawn through the 
vessel by the pistons of the engine. The petrol is used as 
supplied. Petrol being a mixture of different hydrocarbons 
with each its own flash point, no system of petrolizing of air 
can be satisfactory where the air is drawn over a mass of petrol, 
for the air will select first the lighter constituents and leave 
the heavier behind. In all cases the petrol must be put within 
reach of the air in small quantities at once, so that the whole 
portion added is carried off by the stream of air before more is 
added. The evaporation by the air produces a chilling effect 
and raises the flash point of the liquid. Carburettors must 
therefore be warmed by a hot water jacket or by the exhaust 
gases of the engine. 

The lamp oil qualities of paraffin may be atomized by air 
into the space below a perforated disc of metal forming the 
cover of a shallow drum. The vaporized paraffin issues from 
the slits of the burner plate and burns with a blue Bunsen 
flame and this burner is used for small boilers of the flash type. 
The flame keeps the burner plate hot enough to vaporize the 
paraffin in the space below. An initial heater is necessary for 
starting the burner. 



CHAPTER XV 

COMPARISON OF AIR AND STEAM ATOMIZATION 

The Ellis and Eaves System. 

IN this system, the atomizing is done by steam, and heated 
air is supplied to the furnaces, the draught being fan 
induced. The air is heated in tubular heaters having two- 
thirds of the boiler heating surface, and placed over the boiler 
in the course of the gases to the fan, as shown in Fig. 59 ; the 
admission of air to the furnaces being, as in Fig. 60, round the 
outside of the atomizer. 

Tests were also made with air as the atomizing agent. 
The air pressure was 20 pounds per square inch, and the results 
are given below. A subsequent test with air at 35 pounds 
pressure showed 11,108 pounds of water per hour from and at 
212°F. per pound of coal and 15*49 pounds per pound of oil. This 
is somewhat less than with air at the more moderate pressure of 
20 pounds. The atomizing air had a temperature of 80°F. 
only, or it might have given better results. 

The difference between steam and air atomizing seems to be 
practically nil. For land work it remains simply to compare 
the amount of steam used direct with that used in compressing 
the air. 

The analysis of the flue gases showed a mean result of 11-2 
per cent, of C0 2 and 10 per cent, of oxygen in the left hand 
furnace and 14 1 per cent, of C0 2 and 8-4 of oxygen in the 
right hand furnace, the mean of both being C0 2 = 12-6, 
0=9-6, CO =0. 

The tests made with this system of induced draught and oil 
fuel burning, of six hours' duration, were a success, but the 
question was raised whether the system could be worked for a 
lengthened period without giving trouble through deposits of 
soot and unconsumed oil becoming ignited in the air heater and 
casings, and a continuous test of 120 hours was made, careful 
observations being taken of the temperatures, evaporations, etc. 



AIR AND STEAM ATOMIZATION 



223 



Particulars of boiler, wl i3li were the same as in the previous 
tests — 

12 ft. mean diameter by 11 ft. mean length, fitted with two 
Purves furnaces of 3 ft. 9 in. inside diameter. 




Fig. 59. Ellis and Eaves System, Marine Boiler Arrangement, for 

Heating Air. 



148 Serve tubes, 3| in. outside diameter by 7 ft. 9 in. long 
and retarders. 

Heating surface, 1,200 sq. ft. Grate surface (for coal burn- 
ing) 43 sq. feet. 



Position of Oil Burnir$ 




Fig. 60. Ellis and Eaves System, Furnace Door Arrangement. 



Ratio of H.S. to G.S. 28 to 1. 

Fitted with the Ellis and Eaves system of induced draught. 
Surface in air heating tubes, 800 sq. ft. 
Diameter of Fan wheel, 7 ft. 6 in, 



224 LIQUID FUEL AND ITS APPARATUS 

The boiler feed supply was taken from two tanks, each of 
800 gallons and two oil supply tanks for burners, having a 
capacity of about 900 gallons each were provided. The oil 
was fed to burners at 75°F. 

Steam to the burners was supplied at 70 pounds per square 
inch. Texas oil was used, closed flash point 185, calorific 
value 18400 B.Th.U. Sp. gr. 0-915. 

Smoke was visible for a few seconds when changing over the 
oil tanks about every eight hours. Heated air was provided ; 
the difference in right and left hand temperatures of air entering 
the fires being due to the fact that the right hand air heating 
box and air casings are protected from the weather by a wall, 
and also that the air entering these is at a higher temperature, 
due to radiation from the fan discharge. 

The test was started on Monday, December 15, 1902, at 
eleven a.m., the boiler being cleaned before starting, and was 
continued night and day till eleven a.m. on Saturday, December 
20, the installation working without a hitch during the whole 
of that time. Burners required cleaning occasionally, but 
this was carried out one at a time, and only occupied a few 
minutes. Hot air was admitted to the furnaces, the greater 
portion of this only being admitted round about the burners 
through vena-contracta nozzles. 

At the end of the trial the boiler, air heater casings, etc., 
were opened up and examined by representatives of the Wall- 
send Slipway Co. and the International Mercantile Marine Co., 
and found to be perfectly clean and in good order, there being 
no indication of flaming in the casings. From the foregoing 
and a perusal of the following tables, the perfect combustion 
of the oil may be attributed to the use of heated air ; no smoke 
is formed and there is no deposit of inflammable oil or soot on 
the tubes or casings to take fire. 

From the table on page 227 the advantages of air heating are 
shown up clearly. Air which enters the heater at about 54°F. 
leaves it at about 284°F., having taken up 230° of temper- 
ature, all of which is absorbed from the furnace gases, which 
are reduced from about 760°F. to 520°F. more or less. They lose 
the 230° gained by the air, and this alone represents a very 
considerable economy, something like 33 per cent, of the other- 
wise waste heat passing up the chimney. The fan efficiency 
is also increased. Assuming that the furnace temperature is 
2,800°F. the heating of the air by the waste gases would appear 
to represent an economy of fuel of 8 to 10 per cent., apart 
from the higher boiler efficiency due to increased temperature 
head. 



AIR AND STEAM ATOMIZATION 



225 



Air heating is thus advantageous both in economy and more 
perfect combustion. 

Steam Atomization. 



Time. 


Steam 
Pres- 
sure. 


Pan 

E evo- 
lutions 


Vac- 
uum 
at 
Fan 
Suc- 
tion, 


Vac- 
uum 

at 
Fur- 
nace. 


Tem- 
per- 
ature 
of Air 
enter- 
ing 
Heater. 


Heated Air 
entering Fires. 


Escap- 
ing 
Gases 

entering 
Air 

Heater. 


Escap- 
ing 
Gases 
at 
Fan 
Suction. 


Peed 
Water 
Tem- 
per- 
ature. 


Water 
Time 
taken to 
empty 
Tanks. 


Oil. 




Left. 


Eight. 


Tank 
1. 

Mins. 


Tank 

2. 
Mins. 


Gals. 


10-0 


145 


305 2\' 


r 


75°F. 


235°F. 


300°F. 


700°F. 


475°F. 


60°F. 


46 






10.30 


135 


309 21" 


3" 
4 


75° 


235° 


290° 


700° 


475° 


60° 




49 


82| 


11.0 


140 


308 


2£" 


3" 
4 


75° 


232° 


285° 


695° 


470° 


55° 








11.30 


135 


305 2£" 


¥ 


75° 


230° 


285° 


695° 


470° 


58° 


55 




80 


12.0 


140 


300 2\' 


3" 

4 


75° 


227° 


275° 


675° 


455° 


58° 








12.30 


137 


299 


2\" 


4 


75° 


233° 


275° 


700° 


460° 


58° 




41 


81i 


1.0 


140 


308 


21" 


3" 

4 


75° 


242° 


295° 


715° 


485° 


58° 


39 


40 




1.30 


130 


302 


2£" 


r 


75° 


247° 


305° 


710° 


490° 


58° 


100 


2.0 


150 


305 


2£" 


r 


75° 


248° 


308° 


715° 


490° 


58° 




2.30 


145 


305 


21" 


r 


75° 


248° 


305° 


715° 


485° 


58° 


40 


42 


93| 


3.0 


140 


312 


2Y 


r 


75° 


245° 


295° 


705° 


475° 


58° 




3.30 


140 


310 


21" 


r 


75° 


245° 


290° 


705° 


485° 


58° 


135 gals. 

out of 
last tank. 

Total 
6,535 gals. 


82| 


4.0 


145 


309 


2i" 


3'/ 

4 


75° 


246° 


295° 


710° 


505° 


58° 


Total 
530. 



Water evap. per hour. 
Actual observed conditions. 


10,891 
lb. 


Water evap. per lb. of Oil. 
Actual observed conditions. 


13-4 

lb. 


Water evap. per hour, 
from and at 212° Fah. 


13,145 

lb. 


Water evap. per lb. of Oil 
from and at 212° Fah. 


161 

lb. 


Water evap. per sq. ft. H.S. 
Actual observed conditions # 


9 
lb. 


Water evap. per sq. ft. H.S. 
from and at 212° Fah. 


10-9 
lb. 


Theoretical total heat value 
of Oil in lb. of water from 
and at 212° Fah. 


1914 

lb. 


Efficiency of Boiler. 


84% 



The steam tests were of 6 hours' duration, those with air of 
four hours'. 

p 



226 



LIQUID FUEL AND ITS APPARATUS 



Am Atomization. 



Time. 


Steam 
Pres- 
sure. 


Fan 
Revo- 
lutions 
per 
min- 
ute. 


Vac- 
uum 
at 
Fan 
Suc- 
tion. 


Vac- 
uum 

at 
Fur- 
nace. 


Tem- 
per- 
ature 
of Air 
enter- 
ing 
Air 
Heater. 


Heated Air 
entering Fires. 


Escap- 
ing 
Gases 

entering 
Air 

Heater. 


Escap- 
ing 
Gases 
at 
Fan 
Suction. 


Feed 
Water 
Tem- 
per- 
ature. 


"Water 
Time 
taken to 
empty 
Tanks. 


Oil. 




Left. 


Right. 


Tank 

1. 
Mins. 


Tank 

2. 
Mins. 


Gals. 


10.30 


130 


297 


2|" 


H" 


74°F. 


220°F. 


225°F. 


600°F. 


360°F. 


50°F. 


52 






11.0 


130 


297 


w 


H" 


74° 


216° 


245° 


630° 


400° 


50° 




47 


68-4 


11.30 


130 


300 


21* 


H" 


74° 


225° 


250° 


630° 


410° 


50° 








12.0 


130 


300 


2i* 


W 


74° 


225° 


250° 


630° 


410° 


50° 


45 




99-28 


12.30 


130 


298 


2|" 


W 


74° 


223° 


250° 


630° 


410° 


50° 




45 




1.0 


140 


298 


2V 


W 


74° 


223° 


250° 


630° 


410° 


50° 




86-04 


1.30 


140 


298 


2r 


W 


74° 


225° 


250° 


630° 


410° 


50° 






2.0 


140 


298 


21" 


w 


74° 


225° 


250° 


630° 


410° 


50° 


46 




83-83 


2.30 


135 


298 


2|" 


w 


74° 


225° 


250° 


630° 


410° 


50° 


90 gallons 
taken from 
last tank. 






























Total 
4,090 gals. 


Total 
337-55 



Water evap. per hour 
Actual observed conditions. 


10,225 
lb. 


Water evap. per lb. of Oil. 
Actual observed conditions. 


13-24 
lb. 


Water evap per hour, 
from and at 212° Fah. 


12,413 

lb. 


Water evap. per lb. of Oil 
from and at 212° Fah. 


1607 
lb. 


Theoretical total heat value 
of Oil in lb. of water from 
and at 212° Fah. 


19-14 
lb. 


Efficiency of Boiler. 


84% 



AIR AND STEAM ATOMIZATION 



227 



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CHAPTER XVI 

THE STORAGE AND DISTRIBUTION OF LIQUID EUEL 

IN carrying or storing oil, it is necessary to provide for its 
expansion, and it is also necessary to provide a safeguard 
against the rupture of the storage tanks unless these are below 
ground level. Provision must also be made for the escape 
of any gas or vapour generated from the oil and against danger 
from leakage. 

The tanks used for oil storage have a diameter of from 40 
to 70 feet. Some are as large as 90 feet, and the largest will 
hold over one million gallons, or 3,300 gallons per inch of 
depth. To prevent danger, should a tank fail, it ought to 
be surrounded by a moat capable of holding the contents of 
the tank. Both crude oil and the refined products are now 
carried in specially constructed tank steamers, some of which 
will carry as much as 8,500 tons of oil. 

At Liverpool these steamers are discharged through an 
8-inch pipe into vertical tanks of 2,000 and 3,000 tons capacity. 
The carrying space in the steamers is formed by riveted bulk- 
heads across the ship, the skin of the ship itself forming sides 
to the tanks, the screw shaft being laid in a tunnel. Refined 
oil possesses such penetrative properties that the riveting of 
such tanks must be carefully done, and the rivet spacing is 
closer than in ordinary work. The tanks ought to be full of 
oil, and they must not be too large, a bulkhead being placed at 
intervals not wider than 24 feet. These bulkheads must be 
stiff enough to stand the unsupported pressure of the liquid 
upon one side only, together with such extra stress as may be 
caused by the movement of the vessel. The specific gravity 
of petroleum varies considerably, but an approximate rule 
to cover all cases of oil pressure is P = 0-40 H, where P is the 
pounds pressure per square inch and H is the depth in feet below 
the top level of the oil, which may of course be some distance up 
the expansion tanks. 

It is not considered safe to store Texas crude oil nearer to 

228 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 229 

boilers than 500 feet, and in case of a spouting well all fires 
within 500 feet are extinguished. 

Where oil is used freely as fuel it may be lead to the different 
establishments by pipes in preference to carting it in tanks. 
The pipes ought to be of wrought iron or steel, carefully thread- 
ed and fitted together with sound and carefully threaded 
sockets. Pipe joints may be made in three ways : (a) The pipes 
are screwed tapering and the sockets ought to be threaded 
similarly from each end by a tapering tap, so that a tight joint 
may be secured ; (b) Back nuts may be employed to reinforce 
the sockets by aid of an interposed fibrous ring ; (c) The pipe 
ends may be truly faced off exactly at right angles to the axis 
of the threading, a compressible, but thin, washer of soft metal 
or fibre being interposed between the ends of the abutting 
pipes. Such pipes meet together in the sockets like artesian 
drive pipes. 

Ordinary pipes, if found to leak after being put together, 
should be caulked round the ends of the sockets. Before 
screwing together the threads ought to be painted with some 
cement not soluble in petroleum. Litharge and glycerine is 
recommended. Many of the precautions with regard to oil 
arise from the fact that, being lighter than water, it may be 
carried up and down a tidal river and spread a general conflag- 
ration. Being liquid, it will travel by gravity to long distances. 
Where, to avoid danger, oil is stored in buried vaults, there is 
danger of the accumulation of explosive vapours, and ventila- 
tion is required ; the outlet of a ventilating shaft should 
be well exposed and out of such danger as the throwing of a 
lighted match from some point above. Where ventilation 
does not take place freely, it might be necessary to use positive 
means of drawing out the air from a tank chamber or to assist 
the action of the ventilating trunk by a warm water pipe within 
it and a swivelling cowl head. 

To deal with the liquid fuel locomotives of the Great Eastern 
Railway, there were provided a series of underground tanks of a 
capacity in the aggregate of 50,000 gallons, filled direct from 
the travelling tanks of the railway. 

From these underground tanks a Tangye Special pump lifts 
the oil to cylindrical tanks 20 feet above rail level, and of a 
total capacity of 42,000 gallons. 

Outlet pipes controlled by valves, operated from a gallery 
above, conduct the oil to cranes similar to an ordinary water 
crane. 

A main line engine will take in 600 gallons of oil in four or 
five minutes. 



230 LIQUID FUEL AND ITS APPARATUS 

Electric lighting is employed, with portable lamps for the 
cranes or filling arms. 

Oil may be stored underground only, and in airtight tanks, 
which are caused to supply the filling arms by pumping air 
into the tanks above the oil, the air brake pump of the locomo- 
tive itself doing this work. 

The tanks of the tender are filled through a fine gauze strainer, 
protected by a perforated cylinder, so that everything in the 
shape of an obstruction is filtered out, and the gauze also 
serves to prevent ignition of any possible vapour in the tank, 
acting to prevent this on the well known principle of the miner's 
safety lamp. This precaution is more necessary where crude 
oils are used than for the higher flash point residues. 

On the Grazi and Tsaritzin Railway Mr. Urquhart, in his 
1884 x paper gave the length of line worked with petroleum as 
from Tsaritzin to Burnack, 291 miles, and a total of 423 miles, 
including the Volga-Don branch. There is a main reservoir 
for petroleum, at each of the four engine sheds, 66 feet diameter 
and 24 feet high, and about 2,050 tons capacity. The reservoir 
stands a good way from the line and from dwelling houses and 
buildings. 

On a special siding are placed 10 cistern cars full of oil, the 
capacity of each being about 10 tons. Erom each car a connec- 
tion is made by a flexible india-rubber pipe to one of the ten 
standpipes, which project one foot above the ground line. 
Parallel with the rails is laid a main pipe, with which the ten 
standpipes are connected, thus forming one general suction 
main. About the middle of the length of the main, which is 
laid undergound and covered with sawdust or other non- 
conducting material, is a steam pump which in about one hour 
discharges the whole of the cars into the main reservoir. The 
pipes are all wrought iron, lap welded, 5 inch socketed. 

At each shed there is an elevated tank (Fig. 61) 8 J feet dia- 
meter by 6 feet deep, built of J in. plate, to serve as a distribut- 
ing tank to the locomotives. A divided scale shows exactly 
how many poods 2 of oil have been drawn out, the amount 
being corrected for temperature at intervals of 8°R. = 18°F. 
=10°C., the scale ranging from 24°R. to - 24°R. = 86°F. 
to — 22°F., the quantity and temperature being entered in the 
driver's book. The heaviest refuse has a specific gravity of 
0-921 at 0°C. = 32°F., so that 39 cubic feet measure one ton, 
or 57-4 pounds = 1 cubic foot. Lighter refuse has a specific 

1 Proceedings of the Institution of Mechanical Engineers, 1884. 

2 1 pood = 36-114 English pounds = 40 pounds Russian. 62*0257 
poods = 1 ton. 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 231 



Distfibiilikg Tank / 




Fig. 61. 



DISTRIBUTING TANK FOR OlL FUEL. 

Railway. 



Geazi and Tsaritzin 



gravity of 0-889 = 40| cubic feet per ton, or 55 \ pounds per 
cubic foot. 

The engineer-in-charge at each station is provided with a 
hydrometer and thermometer to deal with the ten different 
grades of liquid, each grade having its own peculiar sp. gr. and 
co-efficient of expansion. Table XIII gives useful information 
on this subject. 



Oil Pumps. 

Any pump which will pump water will pump oil, if not too 
viscid. So long as an oil is free from the more volatile hydro- 
carbons, it can be lifted by suction from a depth greater than 
is possible with water, in inverse ratio to its specific gravity. 
By weight a pump will throw less oil than water, but it should 
throw an equal volume. 

For rapidly transferring large bodies of oil from a ship to a 
storage tank, the centrifugal pump is very convenient. There 



232 LIQUID FUEL AND ITS APPARATUS 

are also numerous other rotary pumps of the positive propulsion 
type similar to the Roots' Blower. But viscid oil can hardly 
be moved by a centrifugal pump. 



^x 




Fig. 62. Weir's Oil Pump. 



Valves of india-rubber must of course be avoided, and only 
such substances employed as will resist the solvent action of 
the oil. Metal valves should prove most generally durable and 
efficient. Simplicitv and reliability are the characteristics 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 233 

desired in a pump. For bunker filling especially the pump 
must be of ample capacity, so that a ship may not be long 
detained when calling for fuel in port. 

An example of a bunkering pump is the Weir Patent Pump 
for oil pumping as shown in Fig. 62. This is of the direct 
double-acting type. The valve gear is positive, i.e. the steam 
valve can never be in such a position that the pump will not 
start immediately after the steam is turned on. The valve 
arrangements also ensure constant length of stroke and cer- 
tainty of action. 

The steam valve consists of a " D " slide valve with a small 
auxiliary valve working on the back. These are the only 
moving parts proper in the steam chest, so that there is little 
opportunity for wear and no delicate adjustments to get out 
of order. 

The oil end as shown is fitted with Weir group valves, 
which provide a large area with only a small lift, thus ensuring 
easy working and little wear and tear. In more recent types 
these valves are of the Kinghorn type and the discharge 
branches look upward, not outward. In larger sizes the 
piston rods are divided, and the two are connected by a screwed 
crosshead. 

The pump is specially economical in steam consumption, 
and is simple and with all its parts easily accessible. The 
front elevation shows that there is a separate valve chamber 
for each end of the pump cylinder, the valves being grouped 
on the valve plate round a central valve. With long pump 
buckets there should be no need to use rings. The bucket 
simply requires to be turned a good but free fit in its barrel 
and grooved with square edged grooves J" wide x A* deep, 
spaced about § " centres. This plan is very effectual with water, 
and should be perfect for oil of the consistency of fuel oil. 

Flue Gas Analysis. 

The analysis of flue gases is undertaken for the purpose of 
showing the perfection of the combustion and the excess of air 
employed. 

Considering that about 9 per cent, more coal is consumed if 
the percentage of C0 2 is 8 per cent, instead of 13 per cent., the 
waste of coal will amount to 900 tons a year in 10,000 tons 
burned. Oil stands on the same level. 

In practice, about 1 -3 times the theoretical quantity of air is 
required to effect perfect combustion. 

How much coal is wasted, if the percentage of carbonic acid 



234 



LIQUID FUEL AND ITS APPARATUS 



gas falls to a low level, may be seen at a glance from the follow- 
ing table — 



Percentage of 
C0 2 . . . 
Loss of fuel in 
per cent, 
against the 
theoretically- 
lowest pos- 
sible quantity 



2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


13 


14 


90 


60 


45 


36 


30 


26 


23 


20 


18 


16 


15 


14 


13 



15 



12 



It is not possible to tell from the appearance of the fire in the 
furnace the percentage of C0 2 . 

As one pound of carbon requires a minimum of 11 J pounds of 
air for perfect combustion, it will produce 12 J pounds of total 
furnace gas, and of this 3| pounds will be C0 2 : that is, fully 
29 per cent, by weight or nearly 21 per cent, by volume. For 
anthracite coal free from hydrogen the excess of air can be 
calculated from the percentage of C0 2 in the flue gas. 

For fuels containing hydrogen, the analysis being done cold, 
the steam which is produced by the hydrogen is therefore not 
measured, this steam is less in volume than the nitrogen of the 
air which supplied oxygen to burn the hydrogen. The per- 
centage of C0 2 in the flue gas thus appears smaller with the 
more hydrogenous fuels than it does with the less hydrogenous 
fuel. But in every case the actual percentage can be calculated, 
and, once known, subsequent records can be compared with 
the calculated datum line. 

A fuel containing hydrogen to the extent of one per cent, 
demands 55-9 litres of oxygen per kilo, of coal, or 0-9 cubic 
foot per pound, to satisfy the hydrogen. 

The following tabular numbers give the volume of oxygen per 
kilo, and per pound of coal for various percentages of hydrogen. 



Per cent. 


Litres per kilo. 


Cubic ft. per lb 


1 . . . 


. . . 55-9 . . . 


. . . 0-9 


2 . . . 


. . . 1120 . . . 


. . . 1-8 


3 . . . 


. . . 168-0 . . . 


... 2-7 


4 . . . 


. . . 2230 . . . 


... 3-6 


5 . . . 


. . . 279-0 . . . 


. . . 4-5 


6 . . . 


. . . 336-0 . . . 


. . . 5-4 


7 . . . 


. . . 391-0 . . . 


. . . 6-3 


8 . . . 


. . . 446-0 . . . 


... 7-2 


9 . . . 


. . . 504-0 . . . 


. . . 8-1 


10 . . . 


. . . 559-0 . . . 


. . . 9-0 


11 . . . 


. . . 615-0 . . . 


. . . 9-9 


12 . . . 


. . . 672-0 . . . 


. . . 10-8 


13 . . . 


. . . 727-0 . . . 


. . . 11-7 


14 . . . 


. . . 782-0 . . . 


. . . 12-6 


15 . . . 


. . . 837-0 . . . 


. . . 13-5 


16 . . . 


. . . 892-0 . . . 


. . . 14-4 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 235 

In calculating the volume of dry gas from analysis, any 
hydrocarbon gas is calculated as though it were simply carbon 
vapour of a weight of 1072 grams per litre. 

At 0°C. and 760 mm. pressure, 

Molecular weight 

1 litre of C0 2 = 1-966 gram = 44. 

1 „ „ CO =1-251 „ =28. 

1 „ „ C vapour = 1 072 „ =12. 

Each volume of C0 2 contains -it of its weight of carbon, or 
1-966 x TT = 0-536 grams per litre. Similarly, the proportion 
of carbon in carbonic oxide is f of the weight, or 1-251 x | = 
0-536 grams per litre, the weight of carbon vapour being 1072 
grams per litre. 

Thus the total weight of carbon is C = 0-536 (v + v') + 
1072 v" where v, v' and v" are the volumes of C0 2 , CO, and 
carbon vapour in litres per each cubic metre or per 1,000 volumes 
of flue gas. 

For British units the formula becomes C =00335 (v + v') 
+ 0-06693 v" where v, v' and v" are the volumes in cubic feet 
per thousand feet of flue gas. 

Kent's formula for the weight of dry gas per pound of carbon 
is — 

11, CQ 2 + 80+7 (0 +N ) 
3 (C0 2 + CO) 

Having found this weight of dry gas from the analysis of the 
furnace gases, there must be added the proportion necessary 
for the steam produced. This will measure 9 by weight for 
each unit weight of hydrogen, and, the density of steam being 9, 
the relative volume may be found, or it may be taken from the 
above table. 

By formula the total volume of gases thus becomes. 

+ 55-9 H +A, 



0-536 (v +v') + 1-072*/ 



where H is the percentage of hydrogen in the fuel, and A is the 
combined volume of nitrogen and excess of air. 

In analysing a furnace gas there are two main methods. 
One is to take frequent samples rapidly in a bottle and analyse 
this by the Or sat apparatus : the other is to take a sample, 
known as a long sample, by means of a modification of the 
Sprengel pump, the time of filling the sample bottle being 
extended to any duration wished, even several hours. The 



236 LIQUID FUEL AND ITS APPARATUS 

analysis of this long sample gives the average furnace per- 
formance over the whole time. Short samples may be taken 
and analysed throughout the period of taking the long 
sample. 

For these analyses the Orsat apparatus may be employed 
as most convenient. A description of this will be found in the 
author's work on Liquid Fuel and its Combustion and in manuals 
on gas analysis. There are numerous instruments devised 
automatically to analyse flue gases so far as their contents of C0 2 
is concerned. The Arndt apparatus keeps a continuous record 
of the density of the gases whence the percentage of C0 2 is 
shown by a pointer, and it may be arranged to show a 
continuous record. The Ados apparatus actually analyses 
small samples of the gas every few minutes, and records this on 
a paper band. The apparatus of Simmance and Abady does 
the same thing in a very simple manner. Descriptions of the 
working of these instruments can be had from the makers. 



Calorimeters. 

While the calorific value of a fuel may be calculated approxi- 
mately by Dulong's and other similar formulae, experiment 
must be resorted to for more exact determinations. For 
this purpose a sample of fuel must be actually burned in a very 
complete manner and the heat must be measured which is 
given off. 

Essentially all calorimeters consist of a vessel in which 
a small sample of the fuel to be tested is burned by a stream 
of oxygen. The whole of the heat produced is absorbed by 
water contained in an enclosing case and the calorific power 
is calculated from the rise of temperature of the known 
weight of water and of the metal of the instrument. Various 
corrections have to be made and accurate results are only to 
be obtained with great care. But if a number of samples are 
tested under similar conditions, their comparative values 
may be approximately determined without going to the 
trouble of making corrections which will affect all samples 
alike. 

Descriptions of calorimeters and their method of use maybe 
found in the Author's book on Liquid Fuel and its Combustion, 
and in other works on fuel. 

The following table gives the calorific power of a few oik 
and tars. 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 237 



Calokimetric Values 


by Berthelot Mahler Calorimeter 


Elementary 


Analysis. 






Character of Combustible. 


Carbon. 


Hydro- 
gen. 


Oxygen. 


Nitrogen. 


Calorific 
Value. 


Heavy oil from American 










Cals. 


petroleum .... 


86-894 


13-107 


— 


— 


10,912-7 


Refined American petroleum 


85-491 


14-216 


— 


0-203 


11,045-7 


Treble refined American 












petroleum .... 


80-583 


15-101 


— 


4-316 


11,086 


Crude American oil 


83-012 


13-389 


— 


3-099 


11,094-1 


Heavy Baku oil 


86-700 


12-944 


— 


— 


11,804-6 


Novorossisk petroleum, 












Caucasian .... 


84-906 


11-636 


— 


9-458 


10,328 


Tar from hydraulic main . 


89-910 


4-945 


5-145 


— 


8-9428 


Tar from cooler 


87-222 


5-499 


6-279 


— 


8-8310 


Tar from condenser 


85-183 


5-599 


9-218 


— 


8-8384 



With oil fuel alone the question of draught is of compara- 
tively small importance, for the grate and its load of fuel form 
the chief resistance to draught when solid fuels are used. 

The draught due to a chimney arises from the differ- 
ence of pressure of two columns of gas of the height between 
the grate surface and the chimney-top. The column inside the 
chimney is hot because of the furnace through which it has 
passed. That outside the chimney has the temperature of 
the outer atmosphere. At a temperature of 300°C. (572°F.) 
the inner column is just about double the absolute temperature 
of the outer column, so that the relative density is one-half. 

The velocity of flow of a gas under any head is v = V%g h> 
where v is the velocity in feet per second, h is the head in feet, 
and 2^=64-4 or gravity X 2. Gravity = 32-2. 

Expressed in metres values of v and h we have v = V2 g h, 
where g = 9-81. 

Assuming that at ordinary temperatures 13 cubic feet of air 
weigh one pound, the atmospheric pressure of 2,115 pounds per 
square foot represents a column 27,495 feet in height, which 
would flow into a vacuum at a velocity of approximately 
8V27,495 = 1,321 feet per second. 

The pressure to produce draught, however, is only measured 
by inches of water pressure. If a chimney has an internal 
absolute temperature double that of the external atmosphere, 
it will contain only one pound of gas for each 26 feet of a 
column of gas 1 foot square, or, what is the same thing, the 
external column is half -balanced only. Thus if H be the height 
of the chimney, H -f- (2 x 13) will give the pressure per square 
foot, producing draught. Thus a chimney of 104 feet will 



238 



LIQUID FUEL AND ITS APPARATUS 



give an acting pressure of 4 pounds. As 1 inch of water gives 
a pressure of 036 pounds per square inch, the draught pressure 
of the above chimney would be — 

A 

= 0-7716 inches nearly. 



144 X 036 



Having found the pressure, the air column equivalent to 
this must be found. Water weighs 624 pounds per cubic foot. 
Air weighs 0077 pounds, whence the equivalent air column, in 
feet per inch of water column will be found. 

12x 2 4 077 = 67feet - 



The velocity of flow is then 8 V67 H or fully 64 a/H where H 
is the pressure in inches shown by the actual water gauge. In 
coal-fired furnaces the reading of the draught gauge is much 
greater at the chimney base than in the flues, for the friction of 
the flues exerts considerable resistance. The simplest form of 
water gauge is a bent glass tube of U form, one end being open 
to the atmosphere, the other connected by a piece of india- 
rubber tubing to a piece of pipe which enters the flues at the 
point where the draught intensity is sought. 

It is convenient to remember that where the velocity of 
flow due to head in feet is v=V2 g h, that due to a pressure 
as shown in inches of water is almost exactly z=2gVH. All 
these figures can only be approximate, because they will 
vary with the temperature. They are sufficiently accurate 
to base designs upon in respect of providing sufficient openings 
for air to burn the oil. 

The following table of velocities of air for a few pressures in 
inches of water will be useful — 



Pressure in 


Velocity of air in feet. 




Per second. 


Per minute. 


0-1 
0-2 
0-3 

0-4 
0-5 
0-6 
0-7 
0-8 
0-9 
1-0 
2-0 


20-7 
29-3 
35-8 
41-4 
46-3 
50-7 
54-8 
58-5 
62-1 
65-4 
92-4 


1,243 
1,758 
2,150 

2,485 
2,778 
3,043 
3,287 
3,513 
3,726 
3,927 
5,547 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 239 

An ordinary U gauge is not capable of being finely read. 
It possesses a capillarity which is difficult to allow for and will 
not serve for accurate work. A better gauge consists of a 
glass-fronted box in two divisions partly filled with water. 
A hook gauge, reading on a scale, permits very accurate mea- 
surement. Descriptions of this and other gauges may be 
found in the Author's larger work and in other works on solid 
fuels. But since with solid fuels the greater part of the draught 
is used in overcoming grate resistance the question is of com- 
paratively small importance where liquid fuel alone is em- 
ployed, since unencumbered furnaces and flues with a short 
chimney appear capable of carrying away all the gases from 
liquid fuel. 

In coal firing, about three-fourths of the draught is swal- 
lowed up by grate and fuel friction. With oil firing alone 
and no grate friction there is usually ample velocity of the in- 
flowing air. The chimney, in fact, ceases to possess so much 
importance, but must be large enough in area to carry off the 
waste gases. 

The weight of a cubic foot of air at 0°C. = 32°F. being 
08 lb., that at any other temperature will be 

where t° is expressed in degrees Centigrade 

, 008 x 491 _ . . . _ _ , ... 

anc * " *o i /iKQ where t is m degrees Fahrenheit. 

By these formulae may be calculated the weight of air inside 
and outside a chimney. The difference of the two is the 
pressure to produce draught per foot of chimney height. 

Calling D and d the greater and less densities the equivalent 
height of a column for any chimney of height = h ft. will be 
L = h (2=?) and the velocity of flow per second will be 

v = V2 g L where L is the equivalent column in feet. 

In all the foregoing the specific gravity of furnace gas is 
assumed equal to that of air of the same temperature, the 
steam balancing the carbonic acid more or less closely. 

Seeing that draught is of less importance with liquid fuel, 
it is permissible to reduce the furnace products to a lower 
temperature if facilities can be had for doing this. The smaller 
excess of air with which perfect combustion can be secured is 
a factor in rendering more efficient the heating surfaces of the 
boiler, and reduced flue gas temperatures are a natural con- 
seqence of liquid fuel. 

A chimney must be large enough to pass all the products of 



240 LIQUID FUEL AND ITS APPARATUS 

a furnace at a certain given velocity of flow. The calculation 
of chimney area is thus simple. Assuming the velocity of now 
of gas to be 30 feet per second, it is simply necessary to divide 
the volume of gas produced per second by 30. The result is 
the area in square feet of the chimney. To find the volume 
of gas produced per second, the fuel consumption per second 
is first found as follows in pounds — - 

|f X 2 240 
P = fj o Vaa wnere ^ * s the daily consumption in tons 

and H the daily hours. Then P X 20 = pounds of gas == G. 
At ordinary temperatures one pound of gas measures 13 cubic 
feet very closely. At the chimney temperature it will measure 
20 to 25 feet. Let 22 be assumed : then G X 22 -f- 30 will 
give the area of the chimney inside = A. The chimney will 
measure, if square, VA, on each side, or, if round, its diameter 
will be D=l-12SVA. 

With oil a very small draught will draw in enough air for 
perfect combustion, and it is usually necessary rather to check 
the flow of the gases through the flues, only sufficient draught 
being required to remove the products of combustion as formed. 
Chimneys of small altitude will do this, for they do not require 
to overcome any grate or fuel-bed resistance. In locomotives, 
tor example, the steam blast may be considerably reduced, 
and on the Great Eastern Railway of England the MacAllan 
variable blast-pipe is enlarged from 5 inches with coal to 5f 
inches diameter with oil to the reduction of the back pressure 
on the pistons and economy of steam in consequence. In 
foreign locomotive practice it is usual to employ caps over the 
chimney-top in order to save the loss of heat when running 
down grade or standing idle. Mr. Urquhart continued to use 
this cap with his oil-fired engines, and though it presents an 
odd appearance to English eyes, the cap has advantages. 
Applied to stationary work it is represented ordinarily by a 
damper at the chimney-base, and is thus recognized as good, 
but it is not used in locomotive work. It affords a ready 
means of regulating the fires, and cannot quite be replaced 
by the ash-pit damper, which is heavier to work and is by no 
means always so tight-shutting as it should be. 

A very usual remedy for a bad draught in coal-fired furnaces 
is a steam jet. In oil-firing this aid to draught is present in 
the atomizer, which really replaces the need for a certain 
chimney or fan effect. The area of chimneys must not be 
calculated from the horse-power to be developed. The actual 



STORAGE AND DISTRIBUTION OF LIQUID FUEL 241 

fuel consumption should be worked from. The fuel per horse- 
power hour will vary according to the load-factor and other 
conditions, and large stations will use less fuel per horse-power 
hour than will small stations with smaller load-factors. Each 
case must stand by itself. A very small draught will give a 
velocity of 30 feet per second. Ordinary rules for chimneys 
provide for areas that will reduce the velocity of flow to much 
less than the foregoing 30 feet per second, but it is doubtful if 
such large areas are necessary with liquid fuel, and it is certain 
that a chimney hitherto used for solid fuel will serve well when 
a change is made to liquid fuel. Experience so far is lacking 
on the question of chimney practice for liquid fuel work, but 
the subject may be approached from the standpoint above, 
viz., that with liquid fuel not only is the resistance of the fuel 
on the grate eliminated but there is added a propelling force 
in the atomizer which, if applied to a poor draught in a coal- 
burning furnace, would render such draught good and sufficient. 
Bearing these points in mind, the ordinary treatises on draught 
may be studied with advantage as regards the effect of height 
upon velocity of flow. But the ordinary rules otherwise have 
little application to liquid fuel conditions. 



CHAPTER XVII 

COMPRESSED AIR AND AIR COMPRESSORS 

THE use of air as the atomizing agent has been delayed 
because steam is more readily obtained, and where 
the loss of fresh water in the form of steam is not a serious 
matter, it is claimed that steam is a cheaper agent than air, 
which must be compressed by steam power to begin with. 
But steam is not a supporter of combustion, and air is ; and 
there is a tendency to-day to employ air where possible, 
and to use it hot. Air being so nearly a perfect gas, the whole 
work of compressing it is practically converted into heat, 
and the temperature of the compressed air is raised. In the 
compression of air to 60 pounds per square inch or more it is 
usual to compress in two stages, cooling both cylinders by means 
of a water jacket, and cooling the air between the two stages by 
means of a tubular receiver or a sufficient area of exposed 
tubes. But in fuel atomizing a pressure of 15 pounds to 20 
by gauge is usually held to be ample, and generally it is not 
necessary to use air at the same high pressure as steam. Air is 
much heavier than steam, and more energetic per unit volume. 
But this does not apply to air which must of necessity be intro- 
duced into the furnace and is required for the proper combustion 
of the fuel. Air compressors are somewhat awkward machines, 
and, especially on shipboard, are not easily housed. For oil 
atomizing it is not necessary to employ a two-stage com- 
pressor. The heat of compression is not great for the first 
moderate stage of 15 to 30 pounds, and after the air leaves the 
compressor it should be heated on its way to the atomizer. 
This is usually effected by means of pipes in the flues of the 
stationary boiler or in the smoke-box of the locomotive. 

The curve of isothermal compression of a perfect gas is the 
hyperbola, the equation to the curve being such that Pv = 
constant. 

Thus two cubic feet at 40 pounds absolute pressure become 
one cubic foot at 80 pounds, but the temperature remains 
constant. 

242 



COMPRESSED AIR AND AIR COMPRESSORS 243 

When air is compressed adiabatically, or without loss or 
gain of heat, its curve has the equation — 

v ~ w ; 

P being the pressure corresponding to the small volume v, 
and V the volume at small pressure p. 
Assuming the volume v = 1 we have — ■ 
p v 1 ' 403 

~=-r orP=^V H0S 
p 1 

Thus air at pressure p = 15 is compressed to P == 90. 

P 

Then — = 6 and the relative volumes before and after com- 
V 

pression are for v = 1. 

y 1-403 p 

T =p= 6 

The log. of 6 is 0-77815 

and 0-77815 ^ 1-408 = 0-55266, which is the log. of 3-57 = V. 

Thus in place of an original 6 vols, of air, only 3-57 will be 
needed to give a final volume of 1, owing to the increased 
volume due to temperature rise. For a moderate compression 
of 2 only we shall have V 1 - 408 = 2. The log. of 2 is 0-30103 
and 0-30103 -f- 1-408 = 0-2138, which is the log. of 1-636, 
this being the number of compressions necessary to give a 
double pressure instead of two compressions, had the tempera- 
ture been kept down or V = 1 -636. 

The heat generated in compressing a gas from a pressure of p 
to a pressure of p t is — 

where, 7, according to Rankine, is 1-408 ; p and p t are the 
initial and final pressures in atmospheres and H = foot-pounds, 
T being the absolute temperature whence the heat units per 
pound of air compressed will be H -f- 772, and the temperature 

XT 

772 x 0-237 ' °' 237 being the s P ecific heat of air * 

The work done in compressing and delivering one pound of 
air is thus, in foot-pounds — 

1-4081 /'PAfioe I 
W = 53-15 T —H ? J _i (2) 



244 



LIQUID FUEL AND ITS APPARATUS 




whence can be found the power required for compression. The 
efficiency overall from motor switch-board should not be taken 
above 70 per cent, when 
designing a motor for the 
purpose. The overall 
efficiency of a first-class 
air compressor is said to 
exceed 70 per cent, with 
its electric motor, but or- 
dinary compressors cannot 
be calculated above 50 per 
cent. 

Since free air weighs 
one pound for each cubic 
13 feet at ordinary tem- 
peratures, the size of com- 
pressor required for any 
weight of air is easily 
calculated from the speed 
and piston displacement. 

In a water-cooled compressor the index of the curve of com- 
pression of a good compressor may be safely taken at y — 1 -2 
in place of 1-408, as in adiabatic compression. 

The subject of air compression is one of such importance in 
respect of liquid fuel combustion as to justify full explanation 
of the peculiar action of a perfect gas. 

Air is so nearly a perfect gas that there is very little internal 

work done upon it when 
it is compressed. All 
the work appears as 
heat. In Fig. 63 this 
action is shown dia- 
gramatically. A volume 
of air a b at the pres- 
sure b n of one atmo- 
sphere, if compressed 
to several atmospheres 
so slowly that it loses all 
the heat of compression 
at once, will occupy a 
volume c d at the pres- 
sure a c. 
Fi S' 64 - The area a b n i will 

be exactly equal to the area a c ct m ; in other words, the 
product of pressure and volume is constant. 



c c 


(? * 




^pkf. 











COMPRESSED AIR AND AIR COMPRESSORS 245 

If compressed quickly, without loss of heat, the curve n h 
will be described and the volume of the compressed air will be 
c k. The rectangle d a is equal to the rectangle a n for d and n 
are points in the isothermal curve n d. Consequently the 
rectangles d i and m n must be equal and n k c i is equal to 
m b n k d, or, in words, the mechanical work of adiabatic com- 
pression is equal to the work done in compression and delivery. 

If, in place of single-stage compression, the double-stage 
system be adopted, the principle of intermediate cooling can 
be employed. Thus, in Fig. 64 compression is first carried to 
the point o ; the compressed air is cooled in the receiver to 
the point j, and arrives at the ultimate pressure a c with a 
volume very little greater than c d. The diagram is less in 
area than Fig. 63 by the area jo Jc q, and this represents energy 
economized during compression. 

These same principles and arguments may be applied to the 
use of air in two stages in place of one. Thus, the compressed 
air may be made to run a pump the exhaust from which is 
carried to a hoisting engine or other motor. 

When compressing air the heat of compression is dissipated 
to the atmosphere, and when the air is used again in a two- 
stage expansion it is reheated between the stages by absorption 
of heat from the atmosphere, which thus serves the part of a 
general equalizer, absorbing heat from compressed air and 
giving it out again to expanding air. 

It is stated by Lieutenant Winchell that tests made on vari- 
ous atomizers show that each pound of water evaporated 
from and at 212°F. requires one cubic foot of free air compressed 
to 20 lb. gauge pressure =35 lb. absolute. Assuming that 
1 lb. of oil will evaporate 13 lb. of water, and that 13 cubic feet 
of air are equivalent to 1 lb., the figures represent 1 lb. of air to 
atomize 1 lb. of oil. How much power, then, will be required 
to atomize the fuel for 1,000 h.p., using, say, 16 lb. of steam 
per h.p. hour, with an evaporation, say, of 14 lb. per pound of 
oil? Here 1,000 x if = 1,143 lb. of oil per hour, or 1,143 
lb. of air. This is 19 lb. of air per minute, to compress which, 
according to equation (2) adiabatically from a temperature 
of 62°F.= 522° absol., will require per pound of air — 

per pound of air compressed to 20 lb. gauge pressure per minute. 
At 70 per cent, efficiency, this becomes 1-2 h.p. nearly, or a 



246 LIQUID FUEL AND ITS APPARATUS 

total of 22-8 h.p. for the total engine power of 1,000, which is 
less than 2\ per cent, of the total power ; whereas steam ato- 
mizing requires 3 to 5 per cent, of the total power of a boiler. 
The citation of . the air per pound of evaporation is hardly 
a correct method, but not much is yet known of this part of 
the subject, and meantime one pound of air, or 13 cubic feet 
of free air, should be provided per pound of oil ; and probably 
with the cooling effect allowed for, one brake horse-power will 
compress one pound of air to 20 pounds gauge pressure. The 
figures thus confirm M. Bertin's orginal ideas, as given below. 

The above calculation is for adiabatic compression. 

Per kilogram of air per minute the power expended in air 
compression will be nearly 50 h.p. 

To spray one kilo, of oil requires 28-6 cubic feet of free air, 
or 812 litres. x\s it is usual to order air compressors by their 
capacity in cubic feet of free air, the amount of one unit weight 
per unit of oil works out at 13 cubic feet per h.p. hour, more or 
less, according to the efficiency of steam engine and boilers, or 
from 20 to 25 cubic feet per minute per 100 h.p. From this 
the size of air compressor can be calculated. 

Thus an air compressor will have, say, a total useful piston 
stroke equal to 3 feet per revolution. At 240 revolutions per 
minute, this represents 720 linear feet. With 10 inch dia- 
meter pistons the capacity is thus about 390 cubic feet per 
minute, less, say, 10 per cent, for slip or 350 cubic feet, which 
should supply about 1,400 to 1,700 h.p. of burners in a fairly 
economical plant. An allowance of ten per cent, for slip is 
enough in these compressors for 80 pounds compression, and is 
therefore more than ample for ordinary low pressure work. 

The compressor lends itself readily to electric driving. Auto- 
matic regulating devices are fitted to maintain the air pressure 
constant in the case of electric driving by rheostatic control 
actuated by the air receiver pressure. 

M. Bertin, of the French Navy, states that a good compressor 
will not use half the steam that is used where steam atomizing 
is employed, for steam will compress more than its own weight 
of air up to its own pressure ; and it can hardly be doubted that 
for naval and marine purposes generally the use of air for 
atomizing must eventually become general. 

In the foregoing calculations the compression of the air has 
been assumed to be adiabatic. This is not strictly correct 
even in uncooled cylinders, and some distance from correct- 
ness in cooled cylinders, but any error is on the right side, and 
it is better to proportion the air compressors on an adiabatic 
basis, so that there may be a fair allowance of power. 



COMPRESSED AIR AND AIR COMPRESSORS 247 

As already stated, where the index of the adiabatic curve is 
y = 1 -4, and that of the isothermal curve is y = 1 0, practical 
work may be done at values of y = 1-2. Expanding air be- 
comes so very cold that between the compressor and the ato- 
mizer air should be heated as hot as possible, in order to 
counteract the chilling effect. 

Eor compound compressors, which so far hardly come into 
the sphere of liquid fuel work, the power required to compress 
up to an absolute pressure of 2, 4 or 6 atmospheres is as follows, 
compared with adiabatic compression in a single-stage machine — 



Pressure in Atmospheres. 
Absolute. 


Ratio of Power. 
W 2 ; Wi. 


Probable Ratio 
in practice. 


2 

4 
6 


•951 
•901 
•871 


•975 
•950 
•935 



Even in single-stage compression the actual power required 
in a cooled machine will probably be about midway between 
the figures for adiabatic and two-stage intercooled work. 
See column 3 above. 

As explained elsewhere, the economy of cooling is doubtful ; 
though if there are suitable means of heating the air, it is ex- 
pensive to heat it by expending power upon it. 

In the following table is given the horse-power necessary to 
compress one pound of air to 2, 4 and 6 atmospheres pressure 
absolute from the ordinary temperature of 60°F. = 15-5°C. 
The figures are for adiabatic compression of one pound per 
minute — 



Absolute 
Atmospheres. 


Horse Power. 


Actual h.p. of 
driving motor. 


Gauge Pressure. 


2 
4 
6 


0-645 
1-433 
1-972 


0-860 
1-911 
2-629 


14-7 lb. 
44-1 „ 
73-5 „ 



The difference between adiabatic and isothermal compression 
is of no serious account up to 30 lb., or even to 45 lb. The 
volumetric efficiencies of good compressors at these low pres- 
sures may be safely taken at 90 per cent, of the piston displace- 
ment. The efficiency of the machine being, say, 75 per cent, 
overall from engine to compressor, the indicated horse-power 
actually required will be found by adding one-third to the 
figures in column 2, whence is found column 3. 

Apparently, therefore, air for atomizing may be compressed 
by one horse-power to the extent of about 60 pounds weight per 



248 



LIQUID FUEL AND ITS APPARATUS 



hour. Now, one horse-power in a good steam engine will con- 
sume, say, 16 lb. of steam per hour, or, say, 20 lb. per electrical 
horse-power hour, so that under favourable circumstances 1 lb. 
of steam should compress 3 lb. of air ; and air should, appar- 
ently, be the better agent to employ, quite apart from the 
advantage at sea of not wasting fresh water. Further experi- 
ment is, however, required to afford reliable and fuller figures 
before a hard and fast ruling can be even attempted. The 
Author's own opinion is in favour of air heated to a considerable 
temperature and more or less charged with moisture to assist 
in preventing fouling of the atomizers. 



99 




2 

¥ 


>> 9 
»> 9 


, = iAO 

=778 


„ 


„ 


r 


» J 


= 725 


„ 


»> 


r 


» 9 


= 748 


>f 


„ 


3" 

4 


>> > 


= 898 


»> 


>> 


3" 
4 


99 9 


= 675 



Flow of Air. 

Mr. D. K. Clarke gives the velocity of air flowing from any 
pressure P into any other lower pressure of not more than | 
of P as 880 feet per second. 

Actual experiments upon orifices having a length greater than 
their diameter give about 750 feet per second. 

The following results were obtained — 

50 lb. gauge pressure blowing through §" nozzle to atmosphere = 775 ft. 
30 „ „ „ I' 

45 ,, , t ,, 

•l-O >» >> 99 

25 „ „ 

25 ,, „ ,, 

The last two results were doubtful. 

It will be safe to count upon a velocity of 750 feet in making 
calculations as to the weight of air which will pass an orifice. 
The above velocities are calculated, of course, on the air at the 
higher pressure. The weight of air is proportional to the ab- 
solute pressure, twice as much air escaping at 35 lb. gauge pres- 
sure as at 10 lb., that is to say at 50 lb., and 25 lb. absolute. 

On the relative economy of air or steam for atomizing, Pro- 
fessor Williston says unquestionably that air at 2 to 5 or even 10 
pounds per square inch is more economical than steam, so 
far as the spraying is concerned. At higher pressures there 
is a doubt as to economy, for the cost of compression increases 
rapidly with the pressure, and the atomizing capacity of the 
air does not increase at the same rate. Thus in the U.S. Navy 
tests the most economical results were found with air pressures 
of only one or two pounds. All atomizers will not work at this 
pressure. At these low pressures, however, less than two per 



COMPRESSED AIR AND AIR COMPRESSORS 249 

cent, of the steam generated would compress the air. At an 
air pressure of four or five pounds, four per cent, of the total 
steam was required to compress the air. Obviously, where 
atomizers will act satisfactorily, it will be advantageous to use 
much air at a low pressure in order that the combustion may be 
improved, for air must enter the furnace, and in air atomization 
there is not the risk of fire extinguishment that there is with 
steam. 



CHAPTER XVIII 

THE ATOMIZING OF LIQUID FUEL 

SINCE liquid fuel of the heavy varieties cannot be burned 
except by atomizing, the burner, injector, sprayer or 
atomizer, as it is variously termed, is an important detail. 

Its object is the pulverizing of the liquid, so that, mixed with 
air in the act of pulverization, and supplied with any further 
amount of air that may be necessary, the liquid atoms may 
burn like vapour. 

The spray must not be so directed than an intense blow-pipe 
flame impinges severely upon any small area of furnace plate. 
It is sought to fill the furnace with a full soft voluminous flame 
which shall envelop its whole interior. Given a sufficiently 
long space in front of the burner, a spray directed straight 
ahead and coning out would doubtless produce a satisfactory 
effect, but the space between the point of the burner and that 
part of the cone of flame which first touched the furnace plate 
would be of little use as heating surface. What should be 
aimed at is such a burner and spray device as will produce a 
certain disrupture and outward expanding effect, so as at once 
to spread the oil to a considerable extent normally to the axis 
of the burner as well as parallel ; to give a sort of balloon effect, 
so that, in a locomotive boiler for example, there shall be 
flame well to the back of the box as well as forward under the 
arch. Various forms of atomizers will be found illustrated in 
this or earlier chapters, including — 

The Holden (Figs. 23, 24 and 25). The Billow (Fig. 44). 

The Baldwin (Fig. 34). The Aerated Fuel Co. (Fig. 67). 

The Urquhart (Fig. 42). Kermode's Burners (Figs. 68, 

The Hydroleum Co. (Fig. 71). 69). 

The Swensson (Fig. 73). Odes (Fig. 15). 

The Guyot (Fig. 75). Korting's (Figs. 21, 21a). 

The Rusden and Eeles (Fig. 66). The Hoveler (Fig. 65), p. 267. 

The Holden Atomizer. 

The Holden Injector (Figs. 23, 24, 25) consists of a gun-metal 
casing with oil, air and steam inlets. Air comes in at the back, 



THE ATOMIZING OF LIQUID FUEL 



251 



preferably hot, and is delivered at the point where the oil 
escapes to the inner nozzle. Steam comes between the oil and 
air, and the mixed jet escapes forward and slightly laterally by 
two orifices. A further air supply is directed upon the spray by 
a ring of several fine jets of steam. The atomized fuel is direc- 
ted along the plane of the fire when the fire-bars are retained, 
as this gives the best action. Mr. Holden does not confine 
himself to the use of steam as an atomizing agent, but recognizes 
that air may be preferable for chemical reasons. Two burners 
deal with about six pounds of oil each per mile, or, say, 240 
pounds her hour. 








I 

I 

UJ 

i 

ST£AfiC 

Fig. 66. Atomizer. Rtjsden-Eeles. 

Rusden and Eeles. 

In this burner Fig. 66), steam escapes by a central annular 
jet, and is directed outwards on a fine annular jet of oil, which 
is heated also by a steam jacket. This disposition gives a 
balloon flame. The burner is largely used in marine work. 

The Urquhart. 

This (Fig. 42), one of the earliest successful atomizers, 
employs central steam, external air, and an annular oil jet 
between the two, the expansion of the steam atomizing the oil 
into the air and mixing the two. 



252 LIQUID FUEL AND ITS APPARATUS 

The Baldwin (Fig. 34). 

The burner is very simple, being simply a broad thin jet of 
steam which is directed upon oil escaping from a parallel 
passage. It could not well be simpler, but it is claimed to 
act well, and there appears no reason to doubt this. 

The Aerated Fuel Company's Burner. 

This is of the central air jet type, as shown in Fig. 67. 




Fig. 67. Atomizer. Aerated Fuel System. 

The Kermode Burners. 

The latest type of Kermode burner is the pressure- jet burner 
specially designed for naval and other vessels, and recommended 
for use with forced or induced draught. The burner is shown 
in longitudinal section and in plan respectively in Fig. 68. 
The oil enters through the channel A, and passes between 
the outer wall D and the inner cylinder B, which abuts against 



THE ATOMIZING OF LIQUID FUEL 



253 



the cap-nut E. The end of the cylinder B is an exact fit in D 
where it abuts against the nut E, and in this end of B a number 
of grooves are cut parallel to the centre line of the burner, 
while there are similar grooves in the end of the part B at right 
angles to the axis of the burner. These grooves are shown 
at H, and they are tangential to the cone end of the spindle 
C, which serves to contract, or enlarge, the opening through 
the cup-nut E. The movement of C is indicated on the gradu- 
ated wheel F. 

The oil fuel is pulverized by being forced through a restricted 




Fig. 68. Atomizer. Kermode's Pressure System. 

opening with a rotary motion, which is given to it by the 
tangential grooves in the face of the plug B, and it is distributed 
in the form of a cone by means of the reaction or deflection 
which is set up by the oil impinging on the cone end of the 
spindle C, the pulverization being effected by means of the 
pressure which is brought to bear upon the oil fuel itself by 
means of a force-pump. The oil is heated and filtered. The 
fixed pointer marked G serves to indicate the degree to which 
the wheel F has been rotated, to increase or diminish the 
opening through the nut E. 

Fig. 69 shows a section of the latest Kermode hot-air burner. 
In this burner the oil is partially vaporized and sprayed by hot 
air at a pressure of half to four pounds, the industrial furnace 
working with the former pressure and the naval boiler calling 



254 LIQUID FUEL AND ITS APPARATUS 

for 3 to 4 lb. Oil enters at A, and is regulated by the 
wheel E and the valve on spindle D. Hot air enters at B 
and C and the long helix K gives a rotary motion to the oil and 
air and insures that none of the oil vapour will pass through 
the tube untreated. The supply of air can be regulated at two 
points by means of hand wheels, pinions, and racks ; one pinion 
L moves the internal tube over the oil-delivering nozzle F, 
and regulates the air which enters there. The second pinion 
M operates the outer tube, and varies the amount of air 
escaping around the mixed jet at the end of the twisted spindle 
K. All the elements of the combustion are under complete 
control. The oil as it trickles from the nozzle beyond the valve 
is swept forward by a sharp current of air which envelops the 
nozzle ; this current can be regulated with great exactitude. 
A further compressed air supply is given where combustion 




mm 



Fig. 69. Atomizer. Kermodes Hot Alb System. 



is about to commence, while a third supply is caused by the 
induction of the flame or by the draught ; this latter supply 
comes through the fire-bars, and in special cases through a 
hollow furnace front, passing between the inner and outer 
plate, and escaping through a coned opening around the burner. 
No change in the arrangement of the furnace as designed for 
the use of coal is necessary, and to equip the furnace for burning 
liquid fuel it is only necessary to cover the fire-bars with broken 
fire-bricks to a depth of from 6 to 8 in., the greater depth 
being towards the bridge. The burners are arranged to hinge 
on the air and oil cocks which are attached to the boiler, and 
if it is necessary to examine the front of the burners they can be 
withdrawn from the furnace, the act of withdrawing shutting 
off the supply of air and oil, and thus preventing accident. 

Fig. 70 shows the steam and induced air burner. The oil is 
pulverized by a jet of steam. Oil enters centrally through 
the branch B, and has a whirling motion imparted to it by the 



THE ATOMIZING OF LIQUID FUEL 



255 



stem of the oil valve G. Steam enters around the hollow cone 
H, passing through slots in the cylindrical portion where this 
fits into the hollow of the air cone, the whole oil supply is thus 
steam-jacketed. The air cone is F, and this is also fitted with 
spiral guides. The air is drawn in through these guides by the 
inductive action of the steam, its amount can be adjusted by 



-4 



N 




Fig. 70. Atomizer. Kermode's Steam System. 

opening or shutting the openings D, by means of the movable 
perforated strap E. The front portion F is arranged to screw 
in or out as a whole, being turned by the spider M. In its 
motion it carries with it the air cone F, and thus leaves a greater 
or less space between this and the oil cone H, for the escape 
of steam. The range of adjustment is large, and the same 
burner may be used for different powers within wide limits. 

The HyrtroAeum System. 




Fig. 71. Atomizer. Hydroleum System. 

Fig. 71 shows the nozzle of the Hydroleum Company's burner. 
Oil is centrally regulated by a needle, and issues from a mouth- 
piece flared out externally in such a way as to direct the atom- 
ized spray slightly outwards, the oil being in the middle. The 
oil mouthpiece is in advance of the steam, and an inductive 
action is produced which draws the oil forward when communi- 



256 LIQUID FUEL AND ITS APPARATUS 

cation is opened with the reservoir. The Author has seen this 
burner acting well with tar as fuel. 

External hand wheels regulate the position of the oil and air 
cones, and vary the amount of air allowed to escape round the 

nozzle. 

An elementary form 
of atomizer consists 
simply of two lengths 
of gas pipe, one in- 
side the other for 
the oil and steam. 
In Fig. 72 this is shown developed somewhat, the steam pipe 
being swaged, to form a jet, and drilled to admit the oil. 
The flame of this burner is small, and produces intense local 
heat, and must in boiler work always be accompanied by 
plenty of suitable brickwork. This form is used in various 
forms in South Russia. 

Of self-atomizing oil- jets the Korting (Figs. 21 and 21a) has 




Fig. 72. 




ra 





Fig. 73. Swensson Atomizer. 



been considerably employed at sea, and is described under the 
head of the Korting System, p. 153. 

Another self -spraying oil- jet is the Swensson (Fig. 73), in 
which the oil passes through a fine jet, and is divided into spray 
by striking a cutter placed a little in front of the orifice. These 
self -sprayers have a certain advantage of simplicity. No 



THE ATOMIZING OF LIQUID FUEL 



257 



bulky air pump is required, to compress air, for atomizing the 
oil. There is no waste of fresh water as in steam atomizing. 
A small oil pump will spray all the oil of a large steamship, as 
a simple calculation will show. With a horse-power of 5,000 
there may be used 5,000 pounds of oil per hour, or, say, 10 
gallons per minute, which would fill a three-inch pipe 400 
inches long. Thus a three-inch oil pump with a six-inch 
stroke, if run at sixty- 
seven strokes per 
minute, or, say, thirty- 
four revolutions, would 
feed oil for 5,000 horse- 
power, and two or three 
smaller pumps would in 
practice be employed in 
any ship. The oil 
pumps are thus very 
insignificant in size, and 
this fact will popularize 
the self-spraying ato- 
mizers if they prove 
satisfactory under ordi- 
nary conditions. Of 
course, the oil will not 
spray unless heated 
sufficiently to be limpid 
and easily flowing. If 
too viscous it will spray 
in strings, and not burn 
as thoroughly as it 
should. . 



The Symon-House 
Burner. 





Fig. 74. 



Symon-House Burner and 
Vaporizer. 



This is one of the 
vaporizing burners 
which use the paraffin 
or kerosine grades of oil, a cellular reservoir above the flames 
serving as the vaporizer through which the oil travels in a long 
circuitous course, passing down the pipe to a turned-up jet 
below, this being regulated by a needle, and surrounded by a 
cone which conducts air to the flame. Preliminary heating 
by a lamp of petrol or alcohol is necessary. This burner is 
used for small launch boilers, and is shown in Fig. 74. 



258 



LIQUID FUEL AND ITS APPAEATUS 



It is claimed that in small work atomizing produces too 
intense a heat, and that vaporized petroleum is better. Steam 
can be raised to 100 pounds pressure in twelve or fifteen min- 
utes, and by means of the igniter above the vaporizer the fire 
will relight after several minutes if put out by a sudden jar or a 
gust of wind. The igniter consists of a hollow disc full of 
broken fire-brick. 

In the French navy the Guyot burner has been much used. 
This is shown in Fig. 75, the oil entering centrally and being 
impinged upon by an annular jet of air or steam. The atomiz- 




Fig. 75. Guyot Atomizer. 



ing nozzle should not project as in Fig. 76, but should be kept 
short, as in Fig. 77. 

The Atomizing Agent. 

Though in the early French trials of 1887 as much as 1-2 
pounds of steam was used per pound of oil, the quantity was 
gradually reduced until, in 1893, less than half a pound of 
steam was used in the Godard boiler, says M. Bertin, and in 
1895 M. Guyot got down to as low as 0-25, results which also 
have been obtained in the Italian Navy. Indeed, on a Schichau 
torpedo boat as low as 0-102 is claimed. 

Compressed air, said M. Bertin some years ago, has some 
theoretical advantages, because a given weight of steam will 
compress up to its own pressure a weight of air superior to 
itself, and the pulverizing effect of a jet depends on the energy 



THE ATOMIZING OF LIQUID FUEL 



259 




Fig. 76. 



Nozzle of Guyot Atomizer. 
Incorrect Form. 



of the jet rather than upon its volume. Probably the resis- 
tance of the machine overbalances any theoretical advantage, 
but at sea the loss of fresh water, where a steam atomizer is 
employed, must amount 
to about 5 per cent, of 
the total steam generated. 
M. Bertin, however, said 
that a good air compressor 
will not use half the steam 
necessary where this is 
used direct. When start- 
ing from the cold boiler, 
the compressed air may 
be raised by a small 

compressor driven from a storage battery, by a small petro- 
leum engine, or by hand. Steam atomizing is open to the 
objection that should priming occur the fires may be ex- 
tinguished, and where the steam comes over wet, from a 
priming boiler, it is quite common for burners to be ex- 
tinguished, and the red-hot brickwork fails to ignite the oil, 
and it is necessary to do this by means of a flaming torch. 
Steam should therefore be superheated, both to render it dry 
and to improve its general action. 

M. d' All est found in VAude that atomizing by steam used 
up 15 per cent, of the total steam produced. A little later, 
at Cherbourg, the Torpedo-boat 22 used as little as 1-2 k., 
and the Buffle only 0-75 k., per kilo, of oil pulverized, until 

finally the results as 
detailed above were 
secured, though actual 
facts are not easy to 
obtain, and tests require 
to be undertaken with 
a special boiler to supply 
atomizing steam. Re- 
sults of 0-5 and 0-7 are 
frequently obtained, and 
have gone below 0-3. 
Such a figure as this is 
to be considered very good indeed. To save fresh water at sea 
is so much to be desired that could compressed air be substi- 
tuted for steam it should be. M. Bertin, formerly favourable 
to air as more economical, saw reasons to change his views. 
Air was necessary at much higher pressure than that required 
for forced draught. It is affirmed that 1-4 k. of steam at 6 k. 




Fig. 77. 



Nozzle of Guyot Atomizer. 
Correct Form. 



260 



LIQUID FUEL AND ITS APPARATUS 



pressure must be expended to compress 1 kilo, of air to 1*5 k., 
and more air must be expended to pulverize each unit of oil 
as compared with steam. Thus Torpedo-boat 60 at Cherbourg 
expended 0-6 k. to 0-8 k. of air in place of 04 k. of steam. 

During a test at Indret not less than 0-5 k. of air was 
expended. In brief, with ordinary apparatus to obtain 2 k. of 
air, which is needed to do the work of 1 k. of steam used direct, 
one must use 3 k. of steam in the compression engine. 

The difficulty is that compression is slow in an ordinary 





w/m/hw Win/)///))///)} / > rT//m 



w////////////////////////jv ' ' y//, m 




iyj iuj 



^Jl 



u 



Fig. 78. Boiler of French Torpedo-boat No. 22. 



machine, and steam cannot be used economically, for the air 
attains its highest pressure when the steam is ready to exhaust, 
and a heavy flywheel is necessary to help the expanded steam. 
M. Bertin is further impressed with the physical and chemical 
advantages of steam, which, he affirms, secures the Ragosine 
effect as utilized in the distillation of petroleum without crack- 
ing, owing to a certain solvent action of steam on petroleum, 
as yet little understood. 

The particular form of the Guyot atomizer (Fig. 75) is that 
of Torpedo boat No. 22, the furnace of which is shown in Fig. 
78, the boiler being of return tube type. M. Bertin finds 



THE ATOMIZING OF LIQUID FUEL 



261 



from French experience that though regulation of an oil 
atomizer is most delicately effected by means of the central 
needle of the feed water injector, yet a valve is a less delicate 
detail, and many atomizers have no central moving cone, 
but are regulated solely by valves. 

It is necessary when atomizing that the steam should flow 
at a certain speed. If too rapid, the flame is extinguished ; 
if too slow, there is incomplete pulverization, and the oil escapes 
in drops too large to burn well. 

Hence the steam orifice must be regulated to suit the boiler 
pressure. 

The opening for oil should not be 
less than 1 mm. = 2 V inch. If too 
large the oil flows in too great a 
quantity. It is essential that steam 
or air and oil shall be capable of 
regulation when at work, and that 
the interior of the atomizer should 
be readily removed while at work, 
so that the orifices can be cleared 
quickly and the whole replaced im- 
mediately. 

After numerous experiments with 
atomizers producing both thin flat 
jets, and thin annular or cylindrical 
jets, M. d'Allest devised the atomizer 
of Fig. 79, for which are claimed the 
best results in regularity of effect 
and steady working. It is very Fi 79 
simple in form, and can be rapidly 
dismounted for cleaning. It consists of an outer case con- 
taining an inner cone and spindle ; a steam inlet at the 
side N admits steam to the casing. The whole is attached 
to a conical mouthpiece. Steam is regulated by a valve, 
and escapes round the two cones, while oil comes round the 
central spindle. 

Air is induced through the surrounding opening E. 

The cone can be screwed upon the nose of the case for par- 
tial adjustment of the steam, which is further regulated by a 
valve in the steam pipe. M. d'Allest places these vaporizers, 
if necessary, in couples in one furnace, connecting them to the 
same oil pipe to the number of three, or even four. 

Each burner will dispose of from 10 to 80 kilos. — 22 to 176 
pounds of oil per hour. Two burners, using each 80 kilos, of 
oil, will evaporate 13 kilos, of water per kilo, of oil, or say 2,080 




d'Allest Atomizer. 




262 LIQUID FUEL AND ITS APPARATUS 

litres per hour = 4,576 gallons. Allowing 30 litres per square 
metre of heating surface ; about 6 pounds per square foot ; 
these two burners should serve a boiler of 70 square metres of 

heating surface or 753 
square feet. 

In a torpedo boat, how- 
ever, the desired evapor- 
ation exceeds this amount 
per square metre. With 
this in view, M. d'AUest 
has designed a double 
atomizer, in which oil is 
admitted round the cen- 
tral tube in an annular 
jet. Steam comes out- 
side this, and hot air is 
induced round the whole, 
the heating being effected 
by a tube in the chimney. 
This apparatus (Fig. 80) 
will burn as much as 400 
kilos. = 880 pounds of oil 
per hour without a trace 
of smoke. 
It was tried in VAude, one of the ships of the Compagnie 
Frassinet. A weight of 120 kilos, of oil per hour — 264 
pounds, produced 170 horse-power, the evaporation being 14 1 
units of water per unit of oil, but the French Navy considered 
12 units as the maximum that should be calculated upon. 



Oil 




Stftarn 
Fig. 80. d'Ali/est Double Atomizer. 



Fvardofski System. 

This system applied to locomotives consists in the placing of 
an atomizer in each wall of the furnace two and two exactly 
opposite, the jets meeting centrally and promoting mixture. 
The grate is covered with fire-bricks, between which air enters. 

Though a special pulverizer was used, it would appear that 
any atomizer could be arranged on this system. 

The Brandt burner consisted of a circular box, with a tapered 
slot all round it nearly closed by the edge of a disc. Steam 
escaped under the disc and oil above it. The burner was set 
in the middle of the fire-box and gave a large hollow flame, but 
it had the disadvantage of being inaccessible when at work, 
and the flame was easily extinguished, as by the slipping of the 




THE ATOMIZING OF LIQUID FUEL 263 

wheels of a locomotive, the sudden pull of the blast extin- 
guishing the flame and chilling the box. 

The Soliani burner (Fig. 81) is of simple form, resembling the 
scent spray. 

There are numerous other forms, some complex, others 
crude, but to enumerate all would occupy great space, and 
serve no good purpose. Those illustrated 
will show the general trend of practice and __^-5^. 
what has been done, the chief point being 
apparently that the annular form of jet 
is preferable and conduces to best mix- 
tures. 

The difficulty with burners which 
vaporize has been the deposit of carbon. 
This will occur even with kerosene, the Fi gl g OLIANI 
carbon being a pulverulent coke. The Burner. 

difficulty was got over by M. Serpollet by 
means of easily replaced burners. Heavy oils can then be 
burned. Too high a heat seems to be the cause of carbon 
deposit, the oil being " cracked " exactly as in a highly heated 
still. At present not much is being done by vaporizers, at 
least for large powers, the atomizer becoming more general. 

On the question of pre-heating, the French Naval tests are in 
accord with others as to the advantage of this. 

Long recognized as an advantage to heat to 80°C. = 176°F., 
it is to-day established that Mazout may well be heated to 132° 
C. =269-6°F. 

At this temperature the fuel gives off a certain amount of 
vapour, which raises the pressure in the burner, helps the 
velocity of the jet, and ignites promptly at the nozzle, and 
assists the combustion of the whole. Heating the oil raises 
the efficiency of the combustion, cuts short the flame, and 
increases the effect of the heating surface. 

It is not desirable to generate too much vapour at the orifice 
of the atomizers, or no air can gain access to the jet, and com- 
bustion cannot occur. Air admixture is, of course, necessary, 
and when atomizing is done with compressed air this is a mere 
fraction of the total air required. The air itself is best heated, 
especially if this can be done by recuperation of otherwise 
wasted heat. 

The object of an atomizer is to fill the furnace with flame, and 
the furnace must avoid contact with the flame pending complete 
combustion. The accomplishment of these various ends has 
brought about the many forms of atomizers already described. 
All of them bear a strong family resemblance. In Russia 



£64 LIQUID FUEL AND ITS APPARATUS 

there appears a tendency to employ flat jets. Hence also the 
various forms of furnace with their refractory linings of fire- 
brick, as in Fig. 82 annexed, which represents a boiler made at 
Cherbourg in 1893, and bears a general resemblance to the 
much older forms devised by Urquhart. In this boiler the 
atomizers are placed as shown in the side walls of the furnace. 

Railway practice in America tends to the use of flat jets. 
On the Southern Pacific Railway a simple atomizer, which 
allows the oil to fall from an orifice over the front of a flat 
steam jet, has this jet 3| inches wide. The petroleum escapes 
at an orifice half an inch high and of the length of three inches, 
the steam opening being about 0-8 mm. high, or -gV inch. The 




Fig. 82. Locomotive Type Boiler Tested at Cherbourg with Liquid 

Fuel. 



width of the jet of steam is 3J inches, extending J inch at each 
end below the flow of oil, so that no oil escapes unatomized. 
Flat pulverizers are stated by M. Bertin to be suitable for 
boilers of the Belleville or Niclausse type, in which the flames 
rise directly from the grate to the water-tubes. The broad 
flat flame probably burns over a wide area, and does not enter 
between the pipes so rapidly as if it were a less wide spreading 
jet. 

Should a pulverized jet encounter a cold boiler plate at a 
temperature of 400° to 500°C. =752° to 932°F. 5 the oil will 
condense on the plate and not again ignite. 

In the boiler of Torpedo-boat No. 22 (Fig. 78) the furnace is 
fitted with an air advance chamber in which oil is atomized 
and meets air streams admitted radially. The furnace is 



THE ATOMIZING OF LIQUID FUEL 265 

brick-lined, with a low striking bridge. In this boiler 11*6 
kilo, and 10' 8 kilo, of water have been evaporated per kilo, 
of oil with a draught of 20 to 30 mm. (1 inch mean) of 
water. At heavier draughts of 95 to 110 mm. water gauge 
(or a mean of four inches), only 9*45 k. and 8-5 k. were 
evaporated. A similar boiler, with the air arriving parallel 
with the jet, however, evaporated 13*25 k. of water, which 
shows the difference due to arrangements. 

It may be stated finally, that, of all atomizers, the more 
successful are those which atomize the oil right at the nozzle 
or point of exit. This class appears least liable to choke with 
dirt or to permit of the oil becoming carbonized within the 
body of the atomizer. 

Where atomizers are applied through the furnace door they 
are arranged to swing back upon a trunnion hinge so designed 
as to shut off the fuel supply when the atomizer is swung back. 

The body part on which the atomizer branches are connected 
swivels in the two end pieces through packed glands and these 
end pieces receive the oil and steam or air pipes which supply 
the fuel and atomizing agent. 

The tendency at the present time seems to be somewhat in 
the direction of doing without both air and steam as atomizing 
agents and relying entirely on the pumped pressure of well 
sieved and heated oil to effect the necessary atomization. 

Mixed systems must long continue to be employed, burning 
solid and liquid fuel in the same furnace. 

Twenty years ago the calorific value of the world's oil pro- 
duction was but one-twentieth of the heat value of coal. 
To-day (1921) the ratio has risen to one-tenth, but it is still 
a far cry to the day when coal will be passed in the race, if 
indeed such a day can ever arrive. 

The majority of fuel-burning plants must still be either of 
sclid fuel or of mixed type, and the greater the number of 
all-liquid plants which come into use the less oil will there be 
for other consumers. 

The Gregory Burner, 

This burner (Fig. 82a) consists of a central oil passage 
placed within a steam cone, the oil being regulated by a central 
needle or spindle valve with hand wheel as shown, and the 
steam by. the usual supply valve. Air mixed with highly 
heated furnace gas is drawn by the inductive action of the 
steam into a chamber surrounding the atomizing nozzle, and 
serves to gasify the already heated oil and greatly to aid and 
render perfect its combustion. 



265a LIQUID FUEL AND ITS APPAKATUS 

Suitable clearing plugs are provided. By this burner it 
has been found possible to burn any inferior solid fuels by the 
use of small quantities of oil without smoke, and otherwise 
impracticable fuels may be employed with very considerable 
resulting economy. 

The heated gases, drawn from the furnace, thoroughly dry 
and superheat the steam, the temperature of the mixed vapours 
being moderated by admission of cold air by the inlet indi- 
cated in the figure. 

The burner shown is of locomotive type, but the system is 
equally applicable to stationary boilers and may also be em- 
ployed in furnaces with oil fuel alone. ' 

One of its great advantages is the manner in which inferior 
fuels may be enabled, by the use of a small quantity of oil, 
to improve their combustion by the increment of furnace 
temperature that may be brought about by the oil. This 
is a valuable feature in view of the great amount of inferior 
coal now to be found on the market. This was recognized by 
M. Bertin of the French Navy many years ago, but the Gregory 
burner enables such necessary temperatures to be more readily 
attained. 

Great stress is laid on the gasification of the oil by the hot 
gas. Assuming 1 pound of gas drawn in at 2000 °F. from the 
furnace and a specific heat of 0-25 ; which according to Ber- 
thelot's researches should be much under the truth for high- 
temperature gas ; there will be 500 B.Th.U. added to the oil. 

One pound of oil has a latent heat of vaporization probably 
not over half that of water, so that 1 pound of hot gas should 
fully vaporize 1 pound of oil, and such hot gas would only be 
a small fraction of the weight of the air necessary for com- 
bustion. 

The claims for this burner's good performance thus appear 
to have a properly sound thermal basis. Probably some of 
the good performance may be the result of the gasification 
of the hot oil in an atmosphere giving little or no support to 
combustion, so that the hydrogen is not abstracted too soon, 
leaving the nascent carbon to assume the difficult state of a 
gas carbon similar to the well-known retort carbon of the 
gasworks. 




265B 



CHAPTER XIX 

METALLURGY. THE HOVELER PROCESS 

IT is outside the intended scope of this book to deal very 
seriously with the metallurgical applications of liquid 
fuel. The author dealt with this at some length in Liquid 
Fuel and Its Combustion. 

Since that book was written there has been perhaps fully 
as much progress in the metallurgical application as in power 
application. 

If in a furnace, ore or metal is acted upon too close to the 
point of initial combustion of the oil the flame will be power- 
fully oxydizing and therefore inoperative for reducing work. 
As shown in the above book, the oil must be burned in a separate 
chamber, in advance of the working furnace. 

This is accomplished in the " Hoveler " system by placing 
the oil atomizer, actuated by compressed air at 15 pounds 
pressure, behind a small conical retort lined with refractory 
material. Ignition occurs as the atomized jet enters this cone, 
the flame tapering outwards within the cone and coming out 
by a circular orifice. This apparatus can be carried about on a 
wheeled standard or slung in a chain and placed outside any 
furnace it is desired to heat. The cylindrical bar of flame passes 
through an opening of its own diameter — a few inches — and 
will maintain the interior of a large rotary furnace, or of an air 
furnace at a high temperature. By suitable regulation the 
effect obtained can be oxydizing or reducing according to the 
amount of air admitted. By this system very high efficiency 
of the fuel is obtained, but as in all metallurgical processes 
which involves high temperature work the effluent gases must 
inevitably carry away heat proportionate to the temperature. 

The atomizer of the Hoveler system (Fig. 65) receives the oil 
via a in a central tube h, in which is a needle stem / that con- 
verts the orifice into an annulus c. Compressed air comes via 
b outside the conical end of this oil tube by the tube g and the 
atomized jet is discharged into a cone i, through which atmo- 
spheric air is induced to flow via d. The treble mixture issues 

266 



METALLURGY: THE HOVELER PROCESS 267 

by a parallel opening d projecting through a larger opening e, 
which can be made to supply a further amount of compressed 
air if needed via c. 

For a reducing flame the compressed air is supplied at only 
10 pounds pressure, and in reducing ores or oxides small coal 
may be mixed with the stuff to be reduced, its duty being to 
supply carbon the more energetically to absorb the oxygen 
of the heated material. The use of liquid fuel in metallurgical 
work possesses all the advantages of convenience, cleanliness, 
control and time saving which appertains to its use in steam 
raising, and in metallurgy there is also a marked economy 
in the percentage of reduction and improved product. Though 
much dearer per ton than coal, liquid fuel gains very consider- 




Fig. 65. Hovelee. Atomizer. 

ably by reason ot the amount of it that is not used, for, where a 
heat must be maintained to the last the coal fire is left large 
and active, but the oil flame is shut off at once. Oil gains by 
reason of superior efficiency in the application of the heat pro- 
duced. 



The Aerated Fuel Process. 

This process of the Gilbert and Barker Co. of New York 
is simply a system of atomizing by compressed air, and is used 
in all manner of industrial arts, the flame being used direct 
in metal work, glass making, japanning, etc. The apparatus 
includes an air compressor, oil pump and receiver, storage 
tank and the burners and necessary pipes. 

Compression is to 15 pounds per square inch, a pressure 
below which it is stated that the fuel is not perfectly atomized. 



268 LIQUID FUEL AND ITS APPARATUS 

The oil pump is itself worked by the air, and serves to keep 
a full receiver of about 30 gallons capacity (25 imperial gallons). 
The receiver also contains compressed air which forces 
the oil to the burner (Fig. 67), where it meets the air 
coming direct from the compressor. Valves regulate the 
proportions and the air pressure preserves even working con- 
ditions, whether two or twenty burners are at work. It is 
claimed that the combustion is really gaseous, clean and smoke- 
less. The main supply is a buried tank outside the building 
and away from the burners. The oil pump is automatically 
regulated by a float, and all apparatus is below the burners, 
so that no gravity flow can take place. The use of gravity is 
held by some to be bad practice, and this view will bear argu- 
ment in its favour. Low pressure air is condemned as leading 
to imperfect atomization and large globules which burn 
imperfectly and deposit carbon and injure the fire-brick. 
From 60 to 120 gallons of oil are claimed to do the work of a 
ton of coal. 

The process is held to be much superior to any steam atomiz- 
ing process for metallurgical work. 

Low pressure air which throws oil upon the fire-brick uncon- 
sumed, causes these to shell off and break, and smoke is made 
also while carbon is deposited in the furnace. 

Applied to metallurgy, to forge furnaces, crucible heating, 
and other industrial work outside steam raising, the advantages 
of oil fuel are not merely absence of dirt and dust, but there is 
no loss of time through men waiting for fires to burn up. There 
are no times of good or of bad fires, no uneven heat, but a full 
flowing flame is maintained with an even continuous degree of 
heat. Then the economy of oil is largely secured by increased 
production and better work. Oil has the advantage over gas 
fuel also, which, though equally good in the furnace, cannot be 
produced without labour and dust and at a considerable 
outlay in plant and apparatus. 

The calorific capacity of various gases is as per following 
table— 

Keat Units per 
thousand cubic feet. 



Natural gas 

Air gas (gas machine) 20-candle power 
Public illuminating gas, average . 
Water gas (from bituminous coal) 
Water and producer gas (mixed) . 

Producer gas 

Blast furnace gas 



1,000,000 
815,500 
650,000 
377,000 
175,000 
150,000 
100,000 



Since a gallon of fuel oil (7 pounds) contains 151,000 heat 



METALLURGY: THE HOVELER PROCESS 269 

units, the following comparisons may be made. At three cents 
a gallon (about ISd. per English gallon), the equivalent heat 
units in oil would be equal to — 



Natural gas 

Air gas 20-candle power 
Public illuminating gas, average 
Water gas (from bituminous coal 
Water and producer gas (mixed) 

Producer gas 

Blast furnace gas .... 



Dollars per 
thousand cubic feet, 
at -1987 
•1620 
•1291 
•0749 
•0347 
•0298 
•0200 



At four cents a gallon (about 2 Ad. per English gallon) the 
equivalent heat units in oil would equal — 



Natural gas 

Air gas, 20-candle power . 
Public illuminating gas, average 
Water gas (from bituminous coal 
Water and producer gas (mixed) 

Producer gas 

Blast furnace gas .... 



Dollars per 
thousand cubic feet, 
at -2649 
•2160 
•1722 
•0998 
•0463 
•0397 
•0265 



so that when oil will pay to use it may be installed at one-tenth 
the cost of a gas plant and worked for a fraction of the cost in 
upkeep and wages. 

The Springfield System uses air as low as 18 or 24 ounces 
pressure ; oil comes forward at forty pounds pressure. This 
apparently contradicts the statements above, that low pressure 
air is not satisfactory. Possibly an explanation is to be found 
in the oil pressure which, as in the Korting system, should 
itself do much towards atomizing the oil. Clearly the oil 
must possess energy of itself or borrowed from compressed air 
or steam. 



Colloidal Fuel (1921). 

During the past few years the colloidal state has been 
attracting considerable attention, especially in the direction 
of medicine. 

The term colloidal properly applied appears to pertain to 
a condition or atomic state assumed by substances under 
certain conditions, such for example as the milky condition 



269a LIQUID FUEL AND ITS APPARATUS 

of calcium carbonate when thrown out of solution in water 
when the excess molecule of C0 2 is removed by caustic 
lime. 

So-called colloidal fuel is that modern form produced when 
finely divided carbonaceous matter is mixed with liquid 
hydrocarbons so as to produce by practically a colloidal mix- 
ture or one which will not separate out into a liquid and a 
solid deposit. The continuity of the suspension appears to 
be secured by the use of certain added products known as 
" fixateurs." 

Such a colloidal fuel may be used in an appropriate burner 
and sprayed exactly as fuel oil. 

It has been found practicable with suitable forms of soft 
coals to add as much as 1 -2 pounds of coal to 1 -25 pounds of 
oil, while at the same time the bulk is but little increased. 
In the ordinary way a gallon of oil weighing 9J pounds per 
gallon can be loaded up with coal until it weighs 12 pounds 
per gallon. Obviously the storage capacity of a given bunker 
space is very much increased, for example — 



B.Th.U. B.Th.TJ. 

9-5 lb. of oil at 17,500 = 166,250 

2-5 lb. of coal „ 11,000 = 27-500 



Total in same volume = 193,750 

or, say, 17 per cent, additional calorific capacity per unit of 
bunker space. 

With special coal and the ratio 12-12-5 as above named 
the results are as follows : — 

B.Th.U. B.Th.U. 

1-25 lb. of oil at 17,500 = 21,875 

1-2 lb. of coal „ 10,000 = 12,000 



33,875 



or equivalent to an increased unit calorific carrying power of 
bunkers of 33J per cent. Thus much longer voyages can be 
made without rebunkering. 

The subject is too novel for further reference, but if present 
indications hold good in respect of permanency of condition, 
the subject of colloidal fuel must inevitably come into very 
prominent view. Much is being done by Mr. Lewis, of the 



METALLURGY : THE HOVELER PROCESS 269b 

Fuels Laboratory, Dacre Street, Westminster, to whom I am 
indebted for the foregoing figures, in respect of the chemical, 
physical and mechanical examination of coals generally, and 
many curious and valuable facts are coming to light. 



CHAPTER XX 

THE OIL ENGINE 

OIL or liquid fuel engines may be divided into five classes : 
■ — (a) Those which use the lightest distillates of petro- 
leum. They are known as petrol engines and they are strictly 
only a form of gas engine, for the liquid they use is only admit- 
ted to a vessel through which the engine draws its air supply. 
The air is thus carburetted or petrolized, no liquid molecules 
remaining, and ignition is electrical. It is not intended to treat 
further of this class. 

(b) The paraffine engine which employs the commoner grades 
of lamp oil. 

(c) Crude or heavy oil engines which are fed with heavy 
oils. 

(d) The Diesel engine, in which the fuel is sprayed into pure 
air so highly compressed as to be at a red heat. 

(e) The Griffin engine, which rejects incombustible bases 
such as asphaltum. 

A brief description of the latter four types will be sufficient 
to show the application of liquid fuel to internal combustion 
engines. 

Class b. The Hornsby engine (Fig. 83) may be taken to illus- 
trate this class. On the back cover of the cylinder is fixed a 
bottle neck vaporizer, V, which is first heated by a lamp and is 
afterwards kept hot by the explosions within it when the engine 
has been set to work. 

The back of the cylinder beyond the piston stroke forms, 
with the vaporizer, the compression space/ Air drawn into the 
cylinder on the outstroke of the piston is compressed into the 
vaporizer, into which oil is forced as spray by a small pump 
at the moment of highest compression. The oil is vaporized 
by the heat of the air, and the mixture ignites and expands 
into the cylinder through the bottle neck. The oil pump works 
always at full capacity, but a by-pass allows part of it to 
escape back to the tank. This by-pass is controlled by the 
governor. About 0-55 pint of oil (of -825 sp. gr.) per B.H f P, 

27Q 



THE OIL ENGINE 271 

hour is consumed. The engine will use oil of 0-79 to 0-88 sp. 
gr., and even heavier or crude oil may be used. 

An engine of over 100 B.H.P. was run continuously night 
and day for 500 hours = 21 days. At the end of the time 
there was practically no deposit in the vaporizer and the engine 
would have run a much longer period without loss of power. 
The oil used was the thickest Texas liquid fuel, and at the end 
of the run the engine was working as well as at the beginning. 
The particulars of the run are as below : — 

Rated B.H.P j "° £.H. P. for refined oil 

{ 100 B.H.P. for residual oil. 

Total number of hours running . . . 502 J 

Fuel used . . . Texas, costing 3d. per gallon in tank wagons. 

Specific gravity -933 

Flash point (open test) 240° F. 

Total amount of fuel used .... 15 tons 5 cwt. 1 qr. 17 lb. 

Amount used per hour 68-07 

Average brake horse-power 100*8 

Amount of fuel used per B.H.P. hour .... -578 pints. 

Cost of fuel per B.H.P. hour -21675d. 

Or for 100 B.H.P Is. 9±d. per hour. 

Or 4-6 B.H.P. for Id. per hour. 

The method of injection at the time of ignition probably 
ensures as full a combustion of all the oil as is practicable, none 
depositing before it has had a chance to burn. This helps to 
prevent distillation to destruction or " cracking " which hap- 
pens when oil is too highly heated. The lighter parts are driven 
off as vapour and heavy residuals are left and may accumulate 
in the vaporizers as solid carbon. 

This need not occur with paraffine, which should never be 
made so hot that it will not condense into the same liquid again. 
The carbon difficulty has always attended the use of crude and 
heavy oils, especially when these have an asphaltic base. The 
base remains unconsumed, and when an engine stops and cools 
it becomes glued up by the asphalte. It is better not to use 
such oils in an engine. If such must be used it should, if 
possible, be the practice to run the engine for a time, before 
stopping, with paraffine in order to clear away any varnish- 
like deposit before allowing the engine to stop and cool. See 
class (e). But this is not necessary with ordinary crude oils, 
such as are used in class (c). This class (c) is merely an exten- 
sion of class (b) and includes the above Hornsby engine of which 
the vaporizer is shown in Fig. 83 ; the Ruston-Proctor engine, in 
which a small vaporizing chamber is attached at the back of 
the cylinder and receives the spray of fuel forced in through a 
narrow orifice by which the oil is atomized. As far as 



272 



LIQUID FUEL AND ITS APPARATUS 



possible the oil in this class of engine should be vaporized as 
it enters and not allowed to fall liquid on too hot a surface, by 
which it may be cracked or decomposed with formation of 
solid carbon. 

All kinds of crude oil and residual oils have been tried in the 







v////////. 



wm^ 



'/y//////// t 



Fig. 83. Hornsby Oil Engine Vaporizer. 



Ruston- Proctor engine, varying in sp. gr. from 0-86 to 0-96. 
A special Italian residual oil with 15 to 25 per cent, of tar 
was tried also, and in no case was there any gummy or sooty 
deposit. 

In this class of engine the oil sprays by its own heavy pressure. 
Fuel consumptions are claimed as low as 0-45 lb. per b.h.p. 



THE OIL ENGINE 



273 



hour, but 0-5 lb. should usually be assumed. In the Ruston 
engine a small quantity of water is injected into the cylinder 
at each suction stroke. In the Hornsby engine this water 
injection is not used. The use of water has its advocates and 
the reverse. In its favour are claimed that it is a safeguard 
against overheating at full loads, that it prevents knocking 
from over-hot valves or piston, and obviates risk of cylinder 
scoring and seizing of pistons. 

Class (d) : The Diesel engine occupies this class by itself. 




Fig. 84. Enlarged Cross Section op Vaporizer. 



It depends for its working upon the compression of a charge 
of pure air to so high a pressure — some 35 atmospheres — 
that oil injected into this air will be ignited. Since the air 
charge has a pressure of about 500 pounds per sq. in., the air by 
which the fuel is sprayed into this charge is furnished by a pump 
at about 800 lb. pressure. The engine is best started by com- 
pressed air, a store of which is maintained. The storage vessels 
are sent out, ready charged, with the engine, and serve for 
starting from the first, and the air pressure is carefully main- 
tained so to avoid the inconvenience of hand pumping a fresh 
store. 



274 LIQUID FUEL AND ITS APPARATUS 

The thermal efficiency of the Diesel engine is given by one 
maker as 40*7 per cent, on the indicated horse power, and 31 
per cent, on the brake horse power. The Author's own tests 
fully corroborate these figures. The best steam engines give 
similarly 22 per cent, and 20-5 per cent, with superheated 
steam at 300°C.= 572°F. This of course does not include the 
boiler. Producer gas engines give 20 to 26 per cent. 

Many oil engines work on the Otto cycle, which is a four - 
stroke cycle, but in many Diesel engines, especially for marine 
work, the engine drives an air scavenging pump and the exhaust 
takes place by a ring of ports uncovered by the piston and the 
waste gases are swept out by a scavenging of air, and the engine 
is then run on the two-stroke cycle. 

The use of liquid fuel in the Navy has naturally led up to 
the employment of the oil engine, and the Diesel engine, by 
reason of its economy, has become the accepted type. Its oil 
consumption at full load is about 0-44 lb. of oil per b.h.p. hour. 

Assuming the oil to have a thermal capacity of 19,320 B.Th.U. 
and the heat equivalent of one horse power to be 2,544 
B.Th.U., an engine using 1 pound of oil per h.p. hour would 
have an efficiency of 2,544 -f- 19,320 = 13 1 per cent. The 
efficiency with any other rate of fuel consumption would be 
this last number -; fuel consumption. Thus if the fuel con- 
sumption were 0-4 lb. per h.p. hour, the efficiency would be 
32 per cent, and this may be attained in the Diesel engine. 

The position already taken by the Diesel engine in marine 
work is already good, but as in all four-stroke single acting 
engines, the weight is great for the power developed, and the 
tendency is to convert it into a two-stroke engine and also to 
make it double-acting. This of course demands an exhaust 
uncovered by the piston and a scavenging charge of air to 
sweep out the exhaust gas, but these are details which may 
pertain to all engines and do not apply to the question of the 
fuel used by them, and need not here be further considered. 

Class (d), the Griffin engine, of which Fig. 85 shows a section 
of the vaporizer of a 9J" x 10J" X 4 cyl. engine, occupies this 
class of heavy oil-using engines. 

It is based on the claim that no engine can satisfactorily 
use an oil with a heavy base, particularly an asphaltic base. 
In it, therefore, is embodied an exhaust heated external 
vaporizer. This is first heated by an air blown flame, and serves 
to vaporize the first charge, and it is maintained at about 450°F. 
=r=232°C., by the subsequent exhaust gases. The oil is distilled 
but not cracked ; the heavier portions remain unaltered and are 
run out of the vaporizer by a gravity pipe. The Author has 



THE OIL ENGINE 275 

seen such rejected portion placed on a cold iron plate, and it 
became a hard dry varnish at once, as it would have done 
inside the cold engine if allowed to get in. 

The interior of the Griffin engine remains clear of all deposit 
of carbon or coke or asphalte. There is always found some 
very fine ash in petroleum, and this also is kept out of the 
cylinder, where its presence would produce abrasion. The oil 
is heated in the supply pipe to the vaporizer, as is also the air 
for spraying it in. This facilitates the free flow of the oil, and 
assists in fine atomization. 

The vaporizer, Fig. 85, has an outer jacket marked lOf'dia. 
in this size, surrounding an inner annular chamber 7J" dia., 
which in turn encircles a central vaporizing chamber 5J" dia., 
into which the fuel is sprayed. The exhaust gases from the 
cylinder traverse the annular chamber. Their temperature is 
a maximum of 550°F. = 288°C., which becomes 450°F. = 232°C. 
in the annular chamber. Thus the fuel is vaporized, not gasi- 
fied, a physical and not a chemical change. It is in fact merely 
a fractional distillation which leaves the undesirable refuse to 
be run out of the still as tar or asphalte. The vaporizer is only 
at atmospheric pressure ; it is never exposed to great tempera- 
ture. 

All the air required in the cylinder does not pass through the 
vaporizer. Enough passes that way to carry in the charge of 
oil vapour ; the remainder is admitted by a separate air valve. 
Incidentally this engine is started by a momentum device, the 
fly-wheel having a friction clutch grip on the shaft. A boy can 
gradually get up the fly-wheel of a 40 h. p. engine to a sufficient 
speed ; it is then gripped to the shaft and finds the starting 
energy. 

Ignition is by a refractory body in a small and isolated cavity 
communicating with the combustion chamber. A timing valve 
may be supplied if required. 

The oil and the compressed air by which it is sprayed into 
the heated vaporizer, are both heated so as to render spraying 
more perfect. The temperature of the vaporizer is less than 
that which would gasify the oil, and the tar is left behind in 
place of going forward to the cylinder and doing harm. 

The incombustible ash sticks to the side of the vaporizer and 
can be removed by a wire brush when the engine is stopped. 

The spray injector, which also serves as the heating blow- 
lamp, has an adjustable inner nozzle through which comes air 
at 20 lb. pressure. Oil flows in through an annular chamber 
round this inner nozzle, and is pulverized by the air and 
vaporized by the hot chamber. 



276 



LIQUID FUEL AND ITS APPARATUS 



Both oil and air are supplied at 20 lb. pressure, the oil coming 
from a closed tank to which the air pressure pump has a con- 
nexion, and the supply of oil is regulated by a governor which 




controls the air at the atomizer. There is no change in the 
richness of the mixture supplied but only in its volume, the 
air and the oil being simultaneously varied. 



THE OIL ENGINE 277 

The engine can be started if desirable with light oils, as 
petrol and electrical ignition, the heavy oil being turned on 
when the vaporizer has become hot. This avoids the use 
of the blow-lamp heater in the locality of inflammable 
vapours. 

It should be added that for each 1,000 feet of elevation above 
sea level an engine ought to be about 3 per cent, larger owing to 
the rarefied air. For a number of engines it might be found 
cheaper to pump air to them at a pressure of one absolute 
atmosphere, so that with this compound system no increase of 
engine size need be made. This applies to all oil or gas engines 
when worked at considerable heights above sea level. 

It is external to the intention of this book to afford 
more than an outline of the general systems of using liquid 
fuel in the internal combustion engine, its general mechan- 
ism, etc. 

For details of the legion of different engines, their valve sys- 
tems, sprays, vaporizers, the Author would refer his readers to 
the books of Mr. Dugald Clerk, the late Bryan Donkin and the 
catalogues of makers. 

As the liquid fuel engine is improved, and its operation made 
more and more certain, so will its superior thermal efficiency 
bring it into wider use. There appears to be no immediate 
prospect of a direct oil fuel turbine engine, and all existing 
engines are of the reciprocating type, which steam turbine makers 
have endeavoured with so much success to put out of use for 
steam using. But the turbine runs too fast to suit the propeller 
and this is all in favour of the reciprocating oil engine. At 
present, even the Diesel engine must be run on selected fuel as 
regards freedom from asphalte, etc. Such oils with an asphaltic 
base which might be rejected to the extent of 15 per cent, by the 
Griffin engine would be unsuitable at sea even if their unde- 
sirable elements were rejected by the engine, for no shipowner 
wants to carry the excess of fuel that this implies. On land, 
therefore, any fuel can be used in some engines ; at sea, liquid 
fuel must be selected, except for short journeys. The ability 
to burn any fuel under boilers in high temperature refrac- 
tory furnaces will do much to preserve steam power against 
the inroads of the more highly efficient internal combustion 
engine. The near future will see many oil engines in marine 
work. 

It will be noted that essentially the method of using oil 
in the internal combustion engine is by spraying or atomizing 
the oil into the air with which it is to burn, or by spraying it 
into a vaporizer in which it is evaporated, and whence it passes 



278 LIQUID FUEL AND ITS APPARATUS 

into the cylinder as a vapour. Petrol vaporizes at ordinary 
atmospheric temperature. Heavy oils must have the high 
temperature vaporizer of the Griffin engine, or be directly 
ignited and burned in the highly heated chambers of other 
types of engine or burned in the " red hot " air of the Diesel 
high compression engine. 



Part III 
TABLES 



TABLES 



281 





Table I. 


Compos 


ition of 


Crude 


Oils. 














Per deg. C. 


B.Th.U. 


Name. 


C. 


H. 


0. 


Sp. G. 


Coeff. of 
Expansion. 


Cal. 
Capacity. 


Heavy Virginia 


83-5 


13-3 


3-2 


•873 


•00072 


10,180 


„ Ohio 




84-2 


13-1 


2-7 


•887 


•000748 


10,399 


„ Pa. . 






84-9 


13-7 


1-4 


•886 


•000721 


10,672 


Gas coal oil 






82 


7-6 


10-4 


1-044 


•00744? 


8,916 


E. Galician 






82-2 


12-1 


5-7 


•870 


•000813 


10,005 


W. Galician 






85-3 


12-6 


2-1 


•885 


•000775 


10,231 


Java 






87-1 


120 


0-9 


•923 


•000764 


10,831 


Caucasian . 






85-3 


11-6 


5-1 


•9405 


•000696 


— 


Rangoon 






83-8 


12-7 


3-5 


•875 


•000774 


— 



Table II. Calorific Capacity of Liquid Fuel Oils. 















Calorific 


Locality. 


Fuel. 


Sp. G. 


C. 


H. 


O. 


Capacity. 




o°c. 








Actual 


Calcula- 














Calories 


ted Cal. 


Russian . 


Pet. refuse . 


928 


87-10 


11-7 


1-2 


— 


11,018 


?> 


Astatki . 


900 


84-94 


13-96 


1-2 


10,340 


11,626 


Caucasus . 


Heavy crude 


938 


86-60 


12-30 


1-1 


11,800 


11,200 


American 


Solid residuum 


— 


97-855 


0-489 


1-196 


8,057 


— 


Scotch 


B.F. on . . 


920 


83-64 


10-59 


9-458 


10,328 


— 



Table III. 


Coefficient of Expansion of 


Crude Oils. 




Sp. G. x 1,000. 


Coefficient of 

Expansion of Crude 

OUx 1,000,000 

Dr. Engler. 


Pennsylvania 


816 

828 
829 
841 
861 
862 
870 
875 
882 
885 
887 
899 
892 
892 
901 
944 
955 


840 


Canada 

Alsace 


843 
843 


Virginia 

Alsace 


839 
858 


Wallachia 


808 


E. Galicia 


813 


Rangoon 


774 


Caucasus 


817 


W. Galicia 

Ohio 

Baku 


775 
748 
784 


Hanover (Odesse) 

Pechelbronn 


772 
792 


Wallachia 


748 


Hanover (Oberg) 

Hanover (Wiesse) 


662 
647 



Heavy viscous oils 0-0007 to -00072 between 20° and 78°C=68° to 
172-4°F. containing paraffin and solid below 20° =0-0075 to -00081. 



282 LIQUID FUEL AND ITS APPARATUS 

TABLE V.— THE PROPERTIES OF 





Sym- 
bol. 


Den- 
sity 
H = l 


Mole- 
cular 
Weight 


Lb. 
per 
cubic 
feet. 


Cubic 
ft. 
per 
lb. 


Grams 

per 
Litre. 


Litres 

per 
Gram. 


Required to burn 
one unit. 


Nominal tem 
combu 


Name. 


Weight. 


Volume. 


Air. 




1 


























Air. 


Oxy- 
gen. 


Air. 


Oxy 

gen. 


F°. 


C°. 


Air 


f0 88 ) 


14-44 





•08073 


12-385 


1-29318 


•773 




_ 










Carbon, C — 

Amorphous . 


— 


— 


— 


- 


-{ 


to CO \ 
to C0 2 J 


— 


— 


— 


— 


2673-5 
4938 


1485 
2753 


Vapour 


— 


12 


— 


•06696 


14-930 


1-0727 


•932 


— 


— 


9-54 


2-00 


6955 


3846 


Carbon Dioxide 


co 2 


22 


44 


•12344 


8-147 


•967 


•508 


— 


— 


— 


— 


— 


— 


Carbonic Oxide 


CO 


14 


28 


•07817 


12-80 


1-2515 


•800 


2-484 


•571 


2-381 


•500 


3494 


1923 


Hydrogen . . . 


H 2 


1 


2 


•00559 


178-83 


•08961 


11-16 


34-785 


8-000 


2-39 


•500 


( 
4813 


Wate: 
2674 


Oxygen 
Nitrogen 


o 2 

N 2 


16 
14 


32 

28 


•08926 
•07845 


11-203 
12-763 


1-4298 
1-25616 


•699 
•796 














Steam .... 


H 2 


9 


18 


•05022 


19-912 


•8047 


1242 


— 


— 


— 


— 


— 


— 


Acetylene . 


C 2 H 2 


13 


26 


•07267 


13-456 


1-190 


•840 


13-378 


3-077 


11-93 


2-500 


6120 


3400 


Benzine. 


C 6 H 6 


39 


78 


•208 


4-808 


3-333 


•303 


13-378 


3-077 


35-80 


7-500 


5022 


2790 


Ethylene . . . 
Ethane .... 
Methane 


C 2 H 6 
CH 4 


14 
15 

8 


28 
30 
16 


•07814 
•08565 
•04466 


12-797 
11-950 
22-391 


1-2519 

1-3415 

•7155 


•799 

•746 

1-397 


14-903 

16-484 
17-392 


3-428 
3-733 
4-000 


14-30 

16-70 

9-54 


3-000 
3-500 
2-000 


5400 
4354 
4036 


3000 
2419 
2245 


Ethyl .... 


C 2 H 6 


23 


46 


•12857 


7-775 


2-061 


•287 


9-074 


2-037 


14-30 


3-000 


4630 


2573 


Methyl .... 


CH 4 


16 


32 


•08926 


11-203 


1-4208 


•699 


6-521 


1-500 


7-15 


1-500 


4183 


2325 


Cyanogen . . 


C 2 N 2 


26 


52 


•1453 


6-88 


2-338 


•427 


5-348 


1-23 


9-54 


2-000 


6099 


3388 


Glycerine . 


C 3 H 8 3 


— 


92 


— 


— 


— 




18-148 


4-174 


16-70 


3-500 


4000 


2222 


Blast Furnace Gas 

rcoj 27 n 65 (co 2 ) 6 

H 2 . . . . 


- 


14 + 


— 


•079 


12-65 


1-2515 


•800 


(•100 

(•721 


•22 \ 
•166 J 


•82 


•164 


2160 


1200 


ProducerGas [CO] 25 

(Sundryh-s-tCO^.g 

[CH 4 ] 8 , N 69 . . 

Water Gas iCO] 76 , 

[CH 4 1 2 , [Sundry] 7 - S 

(C0 2 ) 10 N 2 . 5 . . 

Coal Gas, H 8 [CH 4 ] 57 

[CO] 15 N 4 , (Sun- 


- 


14 + 

8 + 


— 


•079 
045 


12-65 
22-5 


1-2515 
•726 


•800 
1-40 


(-99 
\-721 

3-878 


•21 | 
•166] 

•788 


- 


— 


(3440 
12160 

4850 


1910) 
1200) 

2700 


dry) 16 • • . 

Natural Gas(CH 4 ) 90) 

N 6 , Sundry 4 . . 


- 


4-7 
8 


f 

1 


032 
045 


31-6 

22-5 


•516 
1-726 


1-975 
1-40 


13-89 

15-00 


2-81 
3-06 


6-16 


1-23 


4500 
4200 


2500 
2333 



Note.— Gases expand by heat to the extent of ^ of their bulk at 0°C. for each degree Centigrade, or ^ 
The specific heat of gases varies with the tempsrature, being greater for higher temperatures. At the 
Lechateher therefore gives a formula for specific heat C p = 6-5 +aT, where T is the absolute temperature 
4. bis has an important bearing on the thporv of the gas engine. 













TABLES 






283 




3ASES (Kempe's Year Book). 




lerature of 


Heat generated by combustion of one 


Heat of 


Specific Heat. 


ition. 




formation at 
15°C. per 


















Oxygen. 


Lb. 


Cub. ft. 


Gram. 


Litre. 


Molecule. 


Molecule. 


Water = 1. 


F°. 


C°. 


B.Th.IT. 


B.Th.U. 


Cal. 


Cal. 


Cal. 


Cal. 


Liquid. 


Constant. 
























Pressure 


Volume. 




— 


— 


— 


— 


— 


— 


— 


— 


•2375 


1686 


7725 
8440 


4292 
10226 


4415-9 
14647 


— 


2-4533 
8-1375 


— 


29-44 
97-65 


2-84 1 1 
3-343 j 


•2415 


— 


— 


15752 


14290 


20461 


1370-5 


11-3675 


12-193 


136-41 


f — 38-76 2 1 

I— 42-13 | 

68-20 4 \ 


— 


•285 


— 


— 


— 


— 


— 


— 


— 


— 


94-313 \ 
97-65 2 ] 


~ 


216-9 


;171 


lerun 
2892 


.of C.= 
7144 


10232 \ 
4383 J 


f 799-3 
\ 342-5 


f 5-684 
[2-436 


(7-105) 
t 3-047 ) 


68-2 


, 26-13 , 
\ 29-4 2 } 


— 


•245 


:-173 


Vapo 
2108 


ur) f 
6727 j 


52290 
at 32°F. 
62100 


[293 
[347 


( 29-15 
[ 34-50 


[ 2-612 
[ 3-091 


( 58-3 gas N 
\ 69-0 liq. 1 
1 70-4 solid] 


— 


— 


3-410 


•234146 


Water Liquid. 




— 


— 


— 1 — 





— 


— 


— 


— 


•217 


•15481 


— 


— 


— | — 





— 


— 


— 


— 


•244 


•173 














Solid = 70-4 \ 




(1-0 liq. ) 






~ — 


— 


— 


— 


— 


__ 


Liq. =69-0 I 
Gas =58-3] 


per H 2 


i -504 L 
( Solid ] 


•479 


•370 


10340 


11300 


21856 


1624 


12-142 


14-46 


315-7 


—58-1 


— 


•373 


— 


.6830 


9350 I 


18094 \ 
17930 J 


3764 


(10-052 \ 
[ 9-960 J 


33-496 


f 784-1 gas 
1 776-9 liq. 


C — 1-8 sol. \ 
— 4-1 liq. 1 

{— 11 -3 gas] 


•43602 


•3754 


•350 


6886 


9381 


21927 


1744 


12-182 


15-250 


341-1 


—14-8 


— 


•404 


•332 


4848 


8249 


22338 


1912 


12-410 


16-641 


372-3 


23-3 


— 


— 


— 


4348 


7971 


24017 


1073 


13-343 


9-547 


213-5 


18-9 


— 


•593 


•468 


2583 


6690 


12744 


1639-1 


7-080 


14-54 


325-7 


j 59-8 gas I 
I 69-9 liq. J 


f -60 liq. 1 
I -50 gas i 


•451 


•320 


0216 


5675 


9596 


856-5 


5-331 


7-627 


170-6 


f 53-3 gas \ 
\ 61-7 liq. ) 


f -66 liq. 1 
X -46 gas J 


- 


— 


.8222 


10215 


9086 


1320-6 


5-048 


12-02 


262-5 


^—73-9 gas ) 
) —68-5 liq. J 


— 


— 


— 


8078 


4488 


7770 


— 


4-317 


— 


397-2 


f 161-7 Uq. - ! 
1 165-6 sol. J 


— 


— 


— 


4500 


2500 | 


1223 to 
1237 


96-7 } 

97-8 } 


•700 


•900 


— 


— 


— 


— 


— 


4500 


2500 | 


1265 to \ 
2530 J 


100 to 

200 


f -773 to 
1 1-370 


i -9674 to 
\ 1713 


— 


— 


— 


— 


— 




-{ 


4230 to 


330 to 


f 2-35 to 
[3-03 


3-00 to \ 
6-33 i 














5458 


700 












— 


— 


21400 


685 


11-9 


6-099 


— 


— 


— 


— 


— 


— 


- 


24444 


1100 


13-58 


10 


— 


— 


— 


— 


— 


1 From Graphite. 2 From Amorphous Carbon. 3 From Diamond. 


4 From Carbonic Oxide. 


)f their bulk at 32°F. for each degree F.. 




ibsolute zero the values of the molecular heat of all gases seems to converge at 6-5 fo 


r constant pressure values. 


Ceotiffradfi. and a is a co-efficient greater according to the complexity of the molecule. 


For values of a see table. 










(T = 


Temperature 


Centigrade.) 











284 LIQUID FUEL AND ITS APPARATUS 

Table IV. Calorific Power of Crude Oil. 



W. Virginia. 
Oil Creek, Pa. . . 
Java .... 
Baku .... 
E. Galicia . 
W. Galicia . 
Parma .... 
Schwab weiler (Alsace) 



Sp. Gr. 


Cal. Capacity. 


•873 


10190 cals. 


•816 


9963 


•923 


10831 


•884 


11460 


•870 


10005 


•885 


10231 


•786 


10121 


•861 


10458 



Table VI. Temperature. 



Red heat in daylight . 
Iron red in dark . 
Bessemer furnace . 
Common fire 
Copper melts . 
Lead „ 

Tin „ . . . 

Grey cast-iron melts . 
White „ „ „ . 

Carbon vaporizes . 



C°. 



F°. 



577° 


1070° 




400° 


752° 




2205° 


4000° 




595° 


1100° 




1232° 


2160° 




316° 


600° 




215° 


420° 




1100° 


2012° 




1050° 


1922° 




3600° 


6512° 





Table VII. Specific Heats of Gases. 



Air 

Oxygen , 

Nitrogen 

Hydrogen . 
Carbonic oxide, CO 
Carbon dioxide, C0 2 • 
Marsh gas, CH 4 
Olefiant gas, C 2 H 4 
Steam, H 2 . 
Blast furnace gas . 
Steam boiler furnace gas. 



Const. Vol. 


Const. Pressure. 


•168 


•2375 


•1548 


•217 


•173 


•244 


2-4146 


3-410 


•173 


•245 


•171 


•216 


•468 


•593 


•332 


•404 


•370 


•479 


•163 


•228 


•171 


•240 



Cast Iron -1298 

Wrought Iron -1138 

Steel -117 

Brick • , • , ■ , 341 



TABLES 



285 



Table VIII. Equivalents. 

1 Cal 3-968 B.Th.U. 

1 B.Th.U 0-252 CaJ. 

1°C |°F. 

1°F f°C. 

1°C |°R. 

1°R f°C. 

1 kilog 2-204 

1 pound . 0-453 k. 

1 B.Th.U 772 ft. pounds (old). 

778 „ „ (new) 

1 calorie 423-55 k.m. (old). 

. 426-84 „ (new). 

772 ft. p. per 1°F 1389-6 ft. p. per 1°C. 

778 „ „ „ . 1400-4 „ 

423-55 k.m 3063-54 ft. lb. 

426-84 k.m 3087-3 ft. lb. 

1 B.Th.U 107-78 k.m. 

1 k.m 7-231 ft. lb. 

1 k. per linear m 2 lb. per yard nearly. 

1 B.Th.U. per foot 3 9 Cal. per m. 3 „ 

g 32-2 ft. per sec. 2 

g 9-8117 m. per sec. 2 

1 B.Th.U. per ft. 2 2-713 cal. per m. 2 

1 „ „ lb 0-556 cal. per kilo. 

1 kilo, per cm. 2 14-2 lb. per sq. inch. 

1 lb. per sq. inch , . 0-0703 kilo, per cm. 2 

1 metre-kilo 7-231 ft. pounds. 

1 ft. pound 0-138 metre-kilo. 



Table IX. Properties of Carbon Calorifically. 







British 
Thermal Units. 


Temperature 




Calories per 


of Com- 
bustion. 




Mole- 
cule. 


Litre. 


Gram. 


Per 

Cubic Ft. 


Per 

Pound 


In Air. 


Amorphous to CO . 


29-44 


— 


2-453 





44161485° 


2705° 


„ co 2 . 


97-65 


— 


81375 


— 


146472753° 


4988° 


Vapour to CO . 


68-20 


6-096 


5-864 


685-25 


10231 


3540° 


6373° 


C0 2 . . 


136-41 


12-193 


11-3675 


1370-50 


20461 


2846° 


6955° 


CO=2ilb. toC0 2 . 


68-20 


3-046 


5-684 


342-50 


10232 


1923° 


3494° 


CO = lib. toC0 2 . 


29-23 


3-048 


2-436 


342-50 


4384 1923° 3494° 


Hydrogen to H 2 gas 


58-30 


2-612 


2915 


293-00 


52290 2513° 


4554° 


„ H 2 water 


69-00 


3-091 


34-50 


347-00 


62100 2974° 


5385° 



The important figures for practice are in black type. 



286 LIQUID FUEL AND ITS APPARATUS 



Table X. 

TENSION (f.) OF AQUEOUS VAPOUR IN MM. OF MERCURY PER DEGREE 
CENTIGRADE (T.)° AND GRAMS (g.) PER CUBIC METRE OF SATURATED ATR. 



rpo 


g- 


f. 


rpo 


g- 


f. 


to. 


g. 


£. 





— 


4-5 


11 


10-0 


9-7 


22 


19-3 


19-6 


1 


— 


4-9 


12 


10-6 


10-4 


23 


20-4 


20-9 


2 


— 


5-2 


13 


11-3 


11-1 


24 


21-5 


22-2 


3 


— 


5-6 


14 


120 


11-9 


25 


22-9 


23-5 


4 


— 


6-0 


15 


12-8 


12-7 


26 


24-2 


25-0 


5 


6-8 


6-5 


16 


13-6 


13-5 


27 


25-6 


26-5 


6 


7-3 


6-9 


17 


14-5 


14-4 


28 


27-0 


28-1 


7 


7-7 


7-4 


18 


151 


15-3 


29 


28-6 


29-8 


8 


8-1 ' 


8-0 


19 


16-2 


16-3 


30 


29-2 


31-6 


9 


8-8 


8-5 


20 


17-2 


17-4 


— 


— 


— 


10 


9-4 


9-1 


21 


18-2 


18-5 


— 


— 


— 



Table 


XI. 




RELATIVE VALUE OF COAL AND OIL, 


BELATIVE VALUE 


OF COAL AND OIL, ALL 


FUEL ACCOUNT ALONE CONSIDERED. 


ASCERTAINED ECONOMIES CONSIDERED. 


Oil per Barrel at Coal per Ton at Coal per Ton at 


$0-20 $0-74 




$0-65 


0-30 1-12 




0-98 


0-40 1-49 




1-30 


0-50 1-86 




1-63 


0-60 2-24 




1-96 


0-70 2-61 




2-28 


0-80 2-98 




2-61 


0-90 3-35 




2-93 


1-00 3-73 




3-26 


M0 4-10 




3-59 


1-20 4-47 




3-91 


1-30 4-85 




4-24 


1-40 5-22 




4-56 


1-50 5-59 




4-89 


1-60 5-97 




5-22 


1-70 6-34 




5-54 


1-80 6-71 




5-87 


1-90 7-08 




6-19 


200 7-45 




6-52 


1 dollar =48 pence, 


approximately. 





Table XII. Russian and Pennsylvanian Oils. 



Crude Petroleum. 



Penn- 
sylvanian 



Russian. 



Light. Heavy. Refuse, 



Per cent. 



Per cent. 



Per cent. 



Per cent. 



Carbon 

Hydrogen 

Oxygen 

Sp. Gr. at 32°F 

B.Th. Units 

Evaporation at 8 atmospheres 



84-9 
13-7 
1-4 



86-3 

13-6 

01 



86-6 

12-3 

1-1 



87-1 

11-7 

1-2 



100-00 

0-886 
19,210 
16-2 



100-00 

0-884 
22,628 
17-4 



100-00 

0-938 
19,440 
16-4 



100-00 

0-928 
19,260 
16-2 



TABLES 



287 



Table XIII. Petroleum Refuse, 

Specific Gravity and Weight per cubic foot, at various temperatures. 
Water = 1-0000 specific gravity, at 17£° Cent.=63|° Fahr. 





Temperature. 




Specific 


Weight in lb. 


Centigrade. 


Reaumur. 


Fahrenheit. 


Gravity. 


per cubic foot. 





0-0 


320 


0-9110 


56-61 


1 


0-8 


33-8 


0-9103 


56-55 


2 


1-6 


35-6 


0-9097 


| 56-50 


3 


2-4 


37-4 


0-9091 


4 


3-2 


39-2 


0-9085 


56-42 


5 


4-0 


410 


0-9078 


1 56-36 


6 


4-8 


42-8 


0-9072 


7 


5-6 


44-6 


0-9066 


1 56-30 


8 


6-4 


46-4 


0-9060 


9 


7-2 


48-2 


0-9053 


56-20 


10 


8-0 


50-0 


0-9047 


I 56-14 


11 


8-8 


51-8 


0-9041 


12 


9-6 


53-6 


0-9034 


56-11 


13 


10-4 


55-4 


0-9028 


1 56-05 


14 


11-2 


57-2 


0-9022 


15 


12-0 


59-0 


0-9016 


55-99 


16 


12-8 


60-8 


0-9009 


I 55-92 


17 


13-6 


62-6 


0-9003 


18 


14-4 


64-4 


0-8997 


1 55-84 


19 


15-2 


66-2 


0-8991 


20 


16-0 


68-0 


0-8984 


55-81 


21 


16-8 


69-8 


0-8978 


| 55-74 


22 


17-6 


71-6 


0-8972 


23 


18-4 


73-4 


0-8965 


55-68 


24 


19-2 


75-2 


0-8959 


I 55-62 


25 


20-0 


77-0 


0-8953 


26 


20-8 


78-8 


0-8947 


I 55-55 


27 


21-6 


80-6 


0-8940 


28 


22-4 


82-4 


0-8934 


55-48 


29 


23-2 


84-2 


0-8928 


I 55-43 


30 


24-0 


86-0 


0-8922 


31 


24-8 


87-8 


0-8915 


55-37 


32 


25-6 


89-6 


0-8909 


| 55-30 


33 


26-4 


91-4 


0-8903 


34 


27-2 


93-2 


0-8896 


| 55-24 


35 


28-0 


95-0 


0-8890 



288 



LIQUID FUEL AND ITS APPARATUS 



Table XIV. Conversion Table for Degrees Baume, 



Degrees 


Degrees 


Lb. in 1 gal. 


Degrees 


Degrees 


Lb. in 1 gal. 


Baume. 


Sp. Gr. 


(American). 


Baume. 


Sp. Gr. 


(American). 


10 


1-0000 


8-33 


43 


•8092 


6-74 


11 ' 


•9929 


8-27 


44 


•8045 


6-70 


12 


•9859 


8-21 


45 


•8000 


6-66 


13 


•9790 


8-16 


46 


•7954 


6-63 


14 


•8722 


8-10 


47 


•7909 


6-59 


15 


•9655 


8-04 


48 


•7865 


6-55 


16 


•9589 


7-99 


49 


•7821 


6-52 


17 


•9523 


7-93 


50 


•7777 


6-48 


18 


•9459 


7-88 


51 


•7734 


6-44 


19 


•9395 


7-83 


52 


•7692 


6-41 


20 


•9333 


7-78 


53 


•7650 


6-37 


21 


•9271 


7-72 


54 


•7608 


6-34 


22 


•9210 


7-67 


55 


•7567 


6-30 


23 


•9150 


7-62 


56 


•7526 


6-27 


24 


•9090 


7-57 


57 


•7486 


6-24 


25 


•9032 


7-53 


58 


•7446 


6-20 


26 


•8974 


7-48 


59 


•7407 


6-17 


27 


•8917 


7-43 


60 


•7368 


6-14 


28 


•8860 


7-38 


61 


•7329 


611 


29 


•8805 


7-34 


62 


•7290 


6-07 


30 


•8750 


7-29 


63 


•7253 


6-04 


31 


•8695 


7-24 


64 


•7216 


601 


32 


•8641 


7-20 


65 


•7179 


5-98 


33 


•8588 


715 


66 


•7142 


5-95 


34 


•8536 


711 


67 


•7106 


5-92 


35 


•8484 


7-07 


68 


•7070 


5-89 


36 


•8433 


7-03 


69 


•7035 


5-86 


37 


•8383 


6-98 


70 


•7000 


5-83 


38 


•8333 


6-94 


75 


•6829 


5-69 


39 


•8284 


6-90 


80 


•6666 


5-55 


40 


•8235 


6-86 


85 


•6511 


5-42 


41 


•8187 


6-82 


90 


•6363 


5-30 


42 


•8139 


6-78 


95 


•6222 


5-18 



The Sp. Gr. X 10 = weight in pounds per imperial gallon. 



Table XV. Of the Heat of Combustion and Air consumed by various 

Fuels. 



Fuel. 


Oxygen 

per pound 

of fuel. 


Air per pound of 
fuel. 


Total heat 

per lb. of 

fuel. 


Evapora- 
tion from 
and at 
212°F. 


Hydrogen . 
Carbon to C0 2 • 
Average Coal . 
Coke . . . 
Petroleum . 


lb. 
8-0 
2-66 
2-45 
2-49 
3-29 


lb. 
34-8 
11-6 
10-7 
10-81 
14-33 


Cubic ft. 
457 
152 
140 
142 
188 


B.Th.U. 
62,100 
14,647 
14,700 
13,548 
20,411 


lb. 
62-4 
150 
15-22 
14-02 
21-13 



TABLES 



289 



Table XVI. Theoretical Flame Temperatures. 



C to CO . . . 

C to C0 2 . . . 
CO to C0 2 . . 
Hydrogen . 
Marsh gas, CH 4 . 
Olefiant gas, C 2 H 4 
Acetylene, C 2 H 2 . 
Benzine, C 6 H 6 . 
Producer gas . 
Coal gas 
Petroleum . 
Naphthalene . 
Wood . . . . 
Lignite (dry) . 
Coal (bituminous). 



In Air. 


Centigrade. 


Fahrenheit. 


1485° 


2705° 


2753 


4988 


1923 


3494 


2513 


4554 


2245 


4036 


3000 


5400 


3400 


6120 


2790 


5022 


1200 


2160 


2700 


4860 


2400 


4320 


2730 


4914 


2280 


4104 


1200 


2160 


1500 


2700 



Table XVII. Weight and Volume of Gases. 





Wei 


ght. 


Volume. 




Per cubic 


Per cubic 


Per kilogram 


Per pound 




metre in 


foot in 


in cubic 


in cubic 




kilograms. 


pounds. 


metres. 


feet. 


Air 


1-29318 


0-08073 


0-773 


12-385 


Nitrogen .... 


1-25616 


0-07845 


0-796 


12-763 


Oxygen 


1-4298 


0-08926 


0-699 


11-203 


Hydrogen .... 


0-08961 


0-00559 


11-160 


178-83 


Carbonic acid, C0 2 


1-9666 


0-12344 


0-508 


8-147 


Carbonic oxide, CO . 


1-2515 


0-07817 


0-800 


12-800 


Carbon vapour, C . 


1-0727 


0-06696 


0-932 


14-930 


Aqueous vapour, H 2 . 


0-8047 


0-05022 


1-242 


19-912 


Ethylene, C 2 H 4 . . 


1-2519 


0-07814 


0-799 


12-797 


Methane, CH 4 . 


0-7155 


0-04466 


1-397 


22-391 


Acetylene, C 2 H 2 


1-1900 


0-07428 


0-840 


13-456 


Benzine, C 6 H 6 . 


3-3333 


0-208 


0-303 


4-808 


Ethane, C 2 H 6 . 


1-3415 


0-08565 


0-746 


11-950 



290 LIQUID FUEL AND ITS APPARATUS 



I 





o 

1 

60 

o 

u 

ft 

o go 
O 05 

si 

M 

s° 

1 

05 

a 

p 


.a 

d 

a; 


CQ 

■8 

P 

o 

PH 


8-9669 

5-4159 

2-3181 

32-4350 

14-8510 
12-3176 




.a 
< 


03^000 o o 
CO CO 00 O CM OS 
CDQ0H1O lO ■— 1 

qs ■<* qs oo •># 19 

CO ^ rH CO CO i— 1 

<N r-H l-H 




P 
42 

I, 

w CD 

can 

>> 
X 

o 
>> 
pq 


CO 

2 


O O CD O O O 
10 10 000 t- tH 

CO CO OS t- OS OS 
00 00 t> rH i-H i-H 

HHOH "<# CO 
i — 1 




d 

CD 
>> 

o 


O lO CO O O 00 
10(N01»0 00 lO 
CD CO OS 00 OS OS 

oo os co 19 i> co 

h © © O CM CM 


00 

3 
S 


03 tn 


lOlQtOO O CO 
CM CM 00 © OS OO 
CO CO OS t- OS OS 
05 1>H CO I> 

666h rH © 

l-H 


•s. 

r 

CO 


>> 

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"CO P 

o 
o 


CO 

1 

o 

Ph 


<N <mO imO <mO 

■jOOO «0 uSO <? 

^oooffiOrloW 

<N N (N N (N ■* (N N 




■SOOOO O O 

J>CM rH i— 1 l— 1 -<tf CO 


•Is 

1 

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I 5 


1 "^ 

61 

42 


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£_ _ cs, (jq -h -+- 


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t 
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■♦a 

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tH r- tH tJH CM CO 

O OS OS 00 00 OS O 

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Mcm cb cb >b ob »b 

r—t CO rH rH 


O 

CO 

1 




Ph 

i 

n 


< 


Ttf 1> •* Ttf CM CO 

n© OS 00 00 OS o 

aio>"*i> cp qs 
t4<^ ib cm -* i> "* 

^i CO i-H ^-( 


1 


2 

h 

R 


1 CO 

Pm ^ 


.t- CO rH O O 00 

Ocr> CO t- O O (N 

qco cowo 9 -* 
M co <n rH os ib ^h 


o 
>> 


pi 

05 

R 


.OMrtO O OO 
0©Mt-0 O <N 

•r-CO CO IC O O Ttf 

M NHOCO ">* CO 


M 

1— 1 
H 


I 

1 


^oo-hhootHcoooco 

THC<J-*rH-HHCOO0CO 

1! II II II II II II II 


a 

n 


'1 

"05 

1 

05 

1 


CO 

bo 

X 

O 


00 cM 
<N OS 

7 1 

©q co co co O O 

CO rH rH rH 00 <M 




-UIOQ 


(NNQON CD 00 
Hn(M ^ C* 








3 

42 

a 

o 
O 






.... 8 cT 



o 



e co 



5n • 

og 

^a 
2 a 

So 

50 CO 
^^ 

^^ 

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§1 



1 

o 
p< 

CD 
Ph 

CM CD 

CO- 

"^^ 

»1 
IS 

c 

.a 

CD 

| 
o 

> 


.fcl 
>> 

pq 

^3 


I 
1 


J 3lOiO' , ^ rH "^ ^ 

^rf! CD T 1 *? ^ *? 

cS^ 00 ^^ Sq 2 


.ti 

-si 


Cub. ft. 

139-45 
69-72 
30-74 

430-14 

215-50 
184-53 


P 

42 

a 

a s 

be 
O 

pq 


o 

P 

o 

P4 


^'CO CO OS t)H CO CO 

*^op oo i> qs co r-^ 
3 os 6s t>q do t^ r^-i 
g(M(NiHI> co io. 


d 

05 

bD 

X 

o 


^ lO 

■*-co co os i> cq i> 
_£ oo qs co ->* oo co 

P OS ^h CO OS ^ CO 
ONh CO Tt< CO 




^ CO CO OS tH ^ OS 

■m qs qs i^- qs "* r^-- 

3 ^ ^H t>q CO <N (N. 

P.-H r-i r-t t?- CM •-* 


05 

>> 
rQ 

a 
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o 
P. 

i 


CO 

o 

p 

o 
(-1 
Ph 


. <N (M CnO <nO CNlO 

oOOOjO «o « 

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X CD 

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> 


co 

i 05 

42 


Vol. 
IC 
IC 
2C0 
2H 

IC, 4H 
IC, 2H 


3 

A2 

l 

"o 

o 

ft 
Pi 

.SP 

1 


.r1 


CO 

■8 

p 

o 
Ph 


-* t^ tH tH <M CO 

•OS OS CO 00 OS Q 

5>o^ii> co qs 
cm cb co ib cb ib 

t—i CO rH rH 


r 


D 


1 


•<# t^ rH tH CM CO 

A OS OS 00 00 OS o 

— io t> rH i>. cp qs 

rH lb CM Th l> -^ 

>-< CO rH rH 


Bp 

05 


i en 

o -t 3 

P*5 


l> CO rH O O CO 
oCO CO » O O CM 

"co coioo 9 -* 

CO CM rH OS lb li< 


o 


s 

R 

o 


I> CO rH O O 00 
oCO CO l> O O CM 

— CO CO io o o ^ 
CM rH 6 00 TH cb 


-*3 

M 

M 

g 

05 

i 


CO 
C5 

P 
>3 
O 

Pw 


tHOOtHOOtHcDOOcO 
■^CM-^rH^COOOCO 

oooWoWgg 


d 

05 

be 
>i 

O 


32 
16 
16 
16 

80=128 
120 = 12 


•aiqpsnq 
-raoQ 


CM CM 00 CM CD 00 

rH rH CM i-H CM 






CO 

3 

I 

1 






Carbon 

Carbon 

Carb. ox., CO . 

Hydrogen 

Methane, CH 4 
Ethylene, C 2 H 4 



TABLES 



291 



fci 



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| 


<D 




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3 
ft 


| g 2 


CO 


m 


°8 4a 3 


.OOfflM H I— 1 


. O 




£ I>- db l> t> CM 


OS o£ 


r-l i— 1 i— 1 r-H i-H 




^©p, 




£ £ ft 






2 o 

O rv ^ 






The 

Eva 

. of W ate 


T5 


00 C5 lO CO f— I 


^ ■«# !>■ 00 lO CO 
rt M <M © © Th 


CM CM CM CM i-H 


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292 LIQUID FUEL AND ITS APPARATUS 



Table XXI. Ignition Point of Gases (Mayer and Munch), 

Marsh gas, CH 4 667°C, 

Ethane, C 2 H 4 616 

Propane, C 3 H 8 547 

Acetylene, C 2 H 2 580 

Propylene, C 3 H 6 504 



Table XXII. 

Kilos per square metre X -2048 = pounds per square foot. 
Pounds per square foot x 4-884 = kilos, per square metre. 
Kilos, per square cm. x 14-223 = pounds per square inch. 
Pounds per square inch x -0703 = kilos, per square cm. 
Evaporation from 16°C. at 12 kilos, x 0-8222 = evaporation from and 

at 100°C. = 212°F. 
Evaporation from and at 100°C. = 212°F. x 1-216 = evaporation from 

16°C. = 61°F. at 12 kilos. 
Metres x 3-281 = feet. 
Square metres x 10-764 = square feet. 
Feet x 0-3048 = metres. 
Square feet X 0-9308 = square metres. 
Gallons x 4-546 = litres. 
Litres x 0-21998 = gallons. 
Cubic inches x 16-386 = cubic cm. 
Cubic cm. x 0-061027 = cubic inches. 
Gallons (Imp.) X 1*2012 — American gallons. 
American gallons X 0-83226 = English Imp. gallons. 
American gallons X 3*784 = litres. 
Litres x 0-2642 = American gallons. 
Inches water gauge x 25-4 = millimetres water gauge. 
Imp. gallons x 0-1606 = cubic feet. 
Cubic feet x 6-288 = gallons. 
Kilos per metre x 2-015 = pounds per yard. 
Pounds per yard X 0-4962 = kilos, per metre. 
Calories per M. 3 x 0-1121 = B.Th.U. per ft. 3 
B.Th.U. per ft. 3 x 8-92 =' cal. per M. 3 
Calories per M.* x 0-3686 = B.Th.U. per ft.* 
B.Th.U. per ft.* X 2-713 = cal. per Metre*. 



TABLES 



293 



Table XXIII. To determine Temperature by Fusion of Metals. 



Substance. 


Temp. 
Fahr. 


Substance. 


Temp. 
Fahr. 


Substance. 


Temp. 
Fahr. 


Spermaceti . 


120 


Lead . 


619 


Silver, pure 


1,851 


Wax- white . 


154 


Zinc 


754 


Gold coin . 


2,128 


Sulphur . 


239 


Antimony . 


815 


Iron, cast . 


2,074 


Tin . . . 


448 


Aluminium 


1,180 


Steel . . 


2,550 


Bismuth 


512 


Brass . 


1,742 


Wrought iron 


2,911 


Copper . 


2,003 











Table XXIV. Volume and Weight of Dry Air at Different Temperatures 
under a Constant Atmospheric Pressure of 29-92 in. of Mercury, 
the Volume at 32 deg. Fahr. being 1. 



Temperature. 




Weight of 


Temperature. 




Weight of 


Degrees 


Volume. 


a Cubic Foot 


Degrees 


Volume. 


a Cubic Foot 


Fahrenheit. 




in lb. 


Fahrenheit. 




in lb. 





•935 


•0864 


212 


1-367 


•0591 


12 


•960 


•0842 


230 


1-404 


•0575 


22 


•980 


•0824 


250 


1-444 


•0559 


32 


1-000 


•0807 


275 


1-495 


•0540 


42 


1-020 


•0791 


300 


1-546 


•0522 


52 


1-041 


•0776 


325 


1-597 


•0506 


62 


1-061 


•0761 


350 


1-648 


•0490 


72 


1-082 


•0747 


375 


1-689 


•0477 


82 


1-102 


•0733 


400 


1-750 


•0461 


92 


1-122 


•0720 


450 


1-852 


•0436 


102 


1-143 


•0707 


500 


1-954 


•0413 


112 


1-163 


•0694 


550 


2-056 


•0385 


122 


1-184 


•0682 


600 


2150 


•0376 


132 


1-204 


•0671 


650 


2-260 


•0357 


142 


1-224 


•0660 


700 


2-362 


•0338 


152 


1-245 


•0649 


750 


2-465 


•0328 


162 


1-265 


•0638 


800 


2-566 


•0315 


172 


1-285 


•0628 


850 


2-668 


•0303 


182 


1-306 


•0618 


900 


2-770 


•0292 


192 


1-326 


•0609 


950 


2-871 


•0281 


202 


1-347 


•0600 


1000 


2-974 


•0268 



294 



LIQUID FUEL AND ITS APPARATUS 



Table XXV. Table showing Number of British Thermal Units con- 
tained in one pound of pure Water at varying temperatures and 
densities, and pounds per gallon. 



Tem- 
pera- 
ture. 
Deg. 
Fahr. 


Density 

or 
Weight 

of 

1 Cubic 

Foot. 

Pounds. 


Number 

of 

Thermal 

Units 

in 1 

pound of 

Water. 


Pounds 
Weight 

per 
Gallon. 


Tem- 
pera- 
ture. 
Deg. 
Fahr. 


Density 

or 
Weight 

of 

1 Cubic 

Foot. 

Pounds. 


Number 

of 

Thermal 

Units 

in 1 

pound of 

Water. 


Pounds 
Weight 

per 
Gallon. 


1 


2 


3 


4 


1 


2 


3 


4 


*32 


62-418 


32-000 


100101 


135 


61-472 




135-217 


9-859 


35 


62-422 


35-000 


10-0102 


140 


61-381 


140-245 


9-844 


t391 


62-425 


39-001 


10-0112 


145 


61-291 


145-275 


9-829 


40 


62-425 


40-001 


100112 


150 


61-201 


150-305 


9-815 


45 


62-422 


45-002 


10-0103 


155 


61-096 


155-339 


9-799 


50 


62-409 


50-003 


10-0087 


160 


60-991 


160-374 


9-781 


55 


62-394 


55-006 


10-0063 


165 


60-843 


165-413 


9-757 


60 


62-372 


60-009 


10-0053 


170 


60-783 


170-453 


9-748 


65 


62-344 


65-014 


9-9982 


175 


60-665 


175-497 


9-728 


70 


62-313 


70-020 


9-9933 


180 


60-548 


180-542 


9-711 


75 


62-275 


75-027 


9-9871 


185 


60-430 


185-591 


9-691 


80 


62-232 


80-036 


9-980 


190 


60-314 


190-643 


9-672 


85 


62-182 


85-045 


9-972 


195 


60-198 


195-697 


9-654 


90 


62133 


90-055 


9-964 


200 


60-081 


200-753 


9-635 


95 


62-074 


95-067 


9-955 


205 


59-93 


205-813 


9-611 


100 


62-022 


100-080 


9-947 


210 


59-82 


210-874 


9-594 


105 


61-960 


105-095 


9-937 


$212 


59-76 


212-882 


9-565 


110 


61-868 


110-110 


9-922 


230 


59-36 


231-153 


9-520 


115 


61-807 


115-129 


9-913 


250 


58-75 


251-487 


9-422 


120 


61-715 


120-149 


9-897 


270 


58-18 


271-878 


— 


125 


61-654 


125-169 


9-887 


290 


57-59 


292-329 


— 


130 


61-563 


130-192 


9-873 











* 32°F. = Freezing point of water. 

f 39'1°F. = The temperature at which water is at its greatest density. 
+ 212°F. = Boiling point of water. 

A British Thermal Unit (B.Th.U.) = that quantity of heat that is required to 
raise one pound of water through one degree Fahr. at or near 391°F. 



Table XXVI. Saturated Steam. 



Saturated Steam is dry steam at the maximum pressure and density, 
due to its temperature — not superheated. It is attained when all 
latent heat required for the steam has been taken up — this is called 
" Saturation Point." A vapour not near the saturation point behaves 
like a gas under changes of temperature and pressure ; if it is compressed 



TABLES 



295 



or cooled it reaches a point where it begins to condense ; it then no 
longer obeys the same laws as a gas. 

Heat and Work required to generate 1 lb. of Saturated Steam at 212°F from 

Water at 32°F. 







Mechanical 


Distribution of Heat. 


Units of Heat. 


Equivalent in 
foot pounds. 


The Sensible Heat — 






1. To raise the temperature of the 






water from 32°-212° .... 


180-9 


140,740 


The Latent Heat — 






2. In the formation of steam 


894-0 


695,532 


3. In expansion against the atmo- 






spheric pressure 


71-7 


55,783 


Total oe Work 


1,146-6 


892,055 



Table XXVII. Factors of Evaporation. 







Gauge 


Pressure of Steam in 


pounds per Square Inch. 


















Temp, of 













20 


40 


60 


80 


100 


Feed 
Water. 


120 


150 


180 


200 


1-187 


1-201 


1-211 


1-217 


1-222 


1-227 


32 


1-231 


1-236 


1-240 


1-243 


1-179 


1-193 


1-203 


1-209 


1-214 


1-219 


40 


1-222 


1-227 


1-232 


1-234 


1-168 


1-182 


1-192 


1-198 


1-203 


1-208 


50 


1-212 


1-217 


1-221 


1-224 


1-158 


1-172 


1-182 


1-188 


1-193 


1-198 


60 


1-202 


1-207 


1-211 


1-214 


1-148 


1-162 


1-172 


1-178 


1-183 


1-188 


70 


1-191 


1-196 


1-200 


1-203 


1-137 


1-151 


1-161 


1-167 


1-172 


1-177 


80 


1-181 


1-186 


1-190 


1-193 


1-127 


1-141 


1-151 


1-157 


1-162 


1-167 


90 


1-170 


1-176 


1-180 


1-183 


1-117 


1-131 


1-141 


1-147 


1-152 


1-157 


100 


1-160 


1-165 


1-170 


1-172 


1-106 


1-120 


1-130 


1-136 


1-141 


1-146 


110 


1-150 


1-155 


1-159 


1-162 


1-096 


1-110 


1-120 


1-126 


1-131 


1-136 


120 


1-140 


1-145 


1-149 


1-151 


1-085 


1-099 


1-109 


1-115 


1-120 


1125 


130 


1-129 


1-134 


1-138 


1-141 


1-075 


1-089 


1-099 


1-105 


1-110 


1-115 


140 


1-119 


1-124 


1-128 


1-131 


1-065 


1-079 


1-089 


1-095 


1-100 


1-105 


150 


1-109 


1-113 


1-117 


1-120 


1-054 


1-068 


1-078 


1-084 


1-089 


1-094 


160 


1-098 


1-103 


1-107 


1-110 


1-044 


1-058 


1-068 


1-074 


1-079 


1-084 


170 


1-088 


1-092 


1-096 


1-099 


1-033 


1-047 


1-057 


1-063 


1-068 


1-073 


180 


1-077 


1-082 


1-086 


1-089 


1-023 


1-037 


1-047 


1-053 


1-058 


1-063 


190 


1-066 


1-071 


1-076 


1-078 


1-013 


1-027 


1-037 


1-043 


1-048 


1-053 


200 


1-056 


1-061 


1-065 


1-068 


1-004 


1-017 


1-027 


1-033 


1-038 


1-043 


210 


1-046 


1-051 


1-055 


1-057 


1-002 


1-000 










212 











Formula from which the above figures are calculated — 
H=TS-TW. 



F= LS 

TS= Total amount of heat contained in one pound of steam at 
absolute steam pressure — column 4, Table XXVI. 

TW= Total heat of water at feed water temperature — column 3, 
Table XXV. 

H=Heat imparted to water (TW to convert into steam TS), 

LS=Latent heat of steam at atmospheric pressure 965-7. 

F=Factor of evaporation. 



296 



LIQUID FUEL AND ITS APPARATUS 



Saving effected by heating feed water. 
The saving in fuel effected by heating feed water can be calculated 



by formula as below- 



Percentage of saving ; 



100 (T— t) 



H-t 

in which T= heat units in one pound of feed water above 0° after 
heating — column 3, Table XXV. 
t =heat units in one pound of feed water above 0° before 

heating — column 3, Table XXV. 
H=heat units in one pound of steam of boiler pressure above 
0°— column 4, Table XXVI. 



Table XXVIII. 



Heat Balance or Distribution of the Heating Value of 
the Combustible. 



Total Heating Value of 1 lb. of Combustible B.Th.U. 



1. Heat absorbed by the boiler = evaporation from and at 

212 degrees per lb. of combustible x 965-7. 

2. Loss due to moisture in coal=per cent, of moisture 

referred to combustible -*- 100 x [(212 -t) x 966 x 0-48 
(T — 212)]. (t= temperature of air in the boiler 
room, T =that of the flue gases). 

3. Loss due to moisture formed by the burning of hydrogen 

=per cent, of hydrogen to combustible ^by 100 x 9 

X[(212-t x 966 x 0-48) (T— 212)]. 
*4. Loss due to heat carried away in the dry chimney gases 

=weight of gas per lb. of combustible x 0-24 x (T— t). 
f5. Loss due to incomplete combustion of carbon 



CO per cent. C in combustible 



X 10-150 



C0 2 +CO 100 

6. Loss due to unconsumed hydrogen and hydrocarbons, 
to heating the moisture in the air, to radiation, and 
unaccounted for. 

(Some of these losses may be separately itemized 
if data are obtained from which they may be cal- 
culated. ) 



Totals 



B.Th.U. =. 

per cent. 



100-00 



* The weight of gas per lb. of carbon burned may be calculated from the gas 
analysis as follows — 

Dry gas per lb. carbon = H CQ 2 + 8 O + 7 (CO N) 
* 3 (C0 2 + CO) 

in which CO2, CO, O, and N" are the percentages by volume of the several gases. 
The weight of dry gas per lb. of combustible is found by multiplying the dry gas per 
lb. of carbon by the percentage of carbon in the combustible and dividing by 100. 

Professor Jacobus recommends the use of the following formula for finding the 
weight of air per lb. of carbon — 

7 N 
p — -i. n-77 

3 (C0 2 + CO) * " 
f CO2 and CO are respectively the percentage by volume of carbonic acid and car- 
bonic oxide in the flue gases. The quantity 10 150 =number of heat units generated 
by burning to carbonic acid one lb. of carbon contained in carbonic oxide. 



TABLES 



297 



Table XXIX. 

Shoiving Heat Loss in Chimney Gases according to Percentage of 
Carbon Dioxide and Temperature Efficiency. 



lf.0 50 60 70 80 90 10 

8 9 10 11 1Z 13 1U IS 1617 


* S X ^Tu-vvv^ XX 


^ X Xt \ V V 3 A X X - 


^ X v V s S \ I O v 


^ s \- \ v X ^ u\ 


^ ^ x v^a.vv X X. 


^ \ \ ^ \ v X A2LT 


^ \ % X \ ^ SX v3X- It 


^ \ X \ ^ X x v r c 


* ^ x X X x \ X v vu T 


6 ^ ± X s 5 XX Xis Wv - 


-% N - \ \ k \ \ \ \ < \ \ 


^ ^ S V \ \ ^ X xv 


X .. \. . \ \ \ \ \ \ \ N \\ 


X ^ ^ \ V \ A " X X N 


\ ^ \ 242S X v \ A X V L 


X ^ v % S S X4X v\A 


c X ^ V ^X \ \ $ 5 \ \ ^. 


•^ ^ ^22, \X X ,22 


X X \ \ "\ n \ \ \ v \ N N 


^ - X ^ S \ S \ v X-v^R - X 


X X \ \ v ^v V^X VXA X 


V X - ^ \ V X S S X \-VV- X 


X n X V S S v- V VXX 


X \ \ X \ \ ^ S \MxiV 


N '\ \ N \ \ \ v \ v \\\ 


L ^ X N ^ X V S X U\AA-\ 


^ ^ XX ^ s ^2X S \ XXX 


^ \) 2 \ \ \ \ \ N \ \ \X 


x X X \ \ \ ^xxxxx -4- 


^ ^ \ ^ \ X s s\Xa3aS 


\ \ N \ ^ \ \ V , ,,'\ 


\ \ K \ > \ \ \\ \\\ 


-+=k X x ^ - X^ -X -X X a \^ vXA 


v. ^7^ \ \ 2 A . s A , \7\\2 


3 ^ ^^ N ~ N ^ ^ \ N V \\WM X 


"- ^^ X ^ ^ X W\XH 


"^ ^ ^ ^ ^ x X 2 VXXl 


"-. ^^ x ^ x ^ \ \ v^XJ 


^^^ ^^ X X ^^ \ \\XvW\v- 2L 


--, X^ x \^ ^^ "\ X^rV^-Affi 


"^- X ^^ x v \ ^^^ v\^XX 


^^ -t v =v X \ X, 2 \\^X\X 


2 -= -^ ^^ x * s. \\^^55 


"~ = ^= ^^ ^ X ^ \ \~^_vX^a5v- 


--^ "^^ X^ \ r ^^ \\ X^XXlX 


"-^ ^ X=- ^v \\\\^KSt 


~~=.^ "-- ^^ ^ ^ \^v\X5lS^ 


-- ^v- 'v s X \X\\VY\\ 


^"-R2 "" X"--, ^^ ^X\^x22X2\\\y 


- - --^ ^-^ ^^--ir^^SS^SSS- — 


^- it --^ •"' x x^XxrXSs 


1 ~~-=- <= - ^- X^^^^X^SS2 


— -—■-- - 2T X '--^ ^"^ \>X\Sl 


~~ — - -- ^^ ^^ x ^\$yv 


x ^-~— --- ~^ ^vS^§S8| 




— — — ~~^~^_ ^--v^\^^;^\ 


" = "~~~~- — = ~~ ~~ ^ ^ ^ ^ 0^ 


~ — — — ^-^"^^2 


_ - X __ "t- _ ___„i-223 



mz 

1076 
101+0 
100/+ 
963 
93Z 
896 
860 
8Zk 
788 
75Z 
716 
680 
6U8 
612. 
57 Z 
536 
S00 
k6k 
J+Z6 
392 
356 
3Z0 
Z81+ 
ZU.8 
Z1Z 
176 
IkO 
WU. 
68 
3Z 



6Q 



SO 



LO 



60 



10 






INDEX 



Abergele accident, 184 
Acetylene, 289, 82 
Adiabatic compression, 242 
Admiralty flash tests, 130 
Ados, Co 2 recorder, 236 
Advantages of Liquid Fuel, 55 
Aerated fuel system, 267 
Air, atomizing by, 133, 222 

— calculation of, 247 

— compression, 242 

— efflux, 238, 248 

— for atomizing, 133, 214, 222, 

247 

— for combustion, 37, 40, 288, 290 

— for combustion, Rankine, 114 

— for combustion, Longridge, 1 14 

— heater, 166 

— heater, Ellis & Eaves, 223 

— heating, 166 

- — lift pump, 33 

— low pressure, 212, 269 

— power to compress, 242 

— pressure diagram, 242 

— properties of, 82 

— regulator, 202 

— tuyere, 202 
Alcohol, 282 
Allest atomizer, 261 

Alio tropic forms of carbon, 78, 115 
Alsace oil, 46, 281 
American gallon, 44 
American locomotive practice, 162, 
178 

— petroleum, 44 

— petroleum production, 26 

— stationary practice, 195 
Amorphous carbon, 78 
Analysis of Borneo oil, 208, 212 

— chimney gas, 233 

— coal, 112 

— firebrick, 70, 71 

— fireclay, 70, 71 



Analysis of flame, 118 

— flue gases, 233 

— oil, 48 

— petroleum, 48 

— Texas oil, 48 
Anthracite, 139, 116, 111 
Anticline, 30 
Apparatus, Orsat's, 236 
Arch, firebrick, 67 
Area of chimney, 239 
Arlberg tunnel, 171 
Arndt econometer, 236 
Astatki, 36, 65, 208 
Atmosphere, 82 
Atomizers, various, 37, 250 
Atomizer Aerated Fuel Co., 250 

— Baldwin, 179, 250 

— Bereznef, 37 

— BiUow, 196, 207, 250 

— Circular, 36, 262 

— d' Allest, 261 

— elementary, 256 

— flat jet type, 264 

— Fvardofski, 262 

— Gregory, 265 

— Guyot, 250 

— Holden, 157, 250 

— Hoveler, 267 

— hydroleum, 250 

— Kermode's, 250 

— Korting, 153, 250 

— nozzles, 259 

— Orde, 144 

— power of, 259 

— proportions, 261 

— Rusden-Eeles, 134, 250 

— Soliani, 263 

— Southern Pacific Railway, 264 

— Swensson, 250 

— types of, 250 

— Urquhart, 193, 250 

— Wallsend, 148 

— Williams, 56 
Atomizing, 42, 214 



300 



INDEX 



Atomizing, M. Bertin on, 153, 259 

— agent, 214 

— necessity of. 42 

— with air, 133, 214, 222, 247 

— with steam, 133, 214, 222 
Aude, 1', 259 

B 

Baku petroleum, 53 
Baldwin atomizer, 179 

- firebox, 180 

— oil fuel system, 179 
Ballast tanks, 129 
Barometer, 83 

Barrels of oil produced, 26 

— and gallons, 49 
Beaumont oil, 39, 50 

— tests, 56 
Bereznef atomizer, 36 
Berthelot on carbon, 79 
Berthelot-Mahler calorimeter, 91 
Berthelot on latent heat of carbon, 

79 
Bertin on air compressing, 246 

— on atomizing, 153 

— on liquid fuel, 37 

— on mixed system, 37, 172 

— on ratio of oil and coal, 38 
Billow atomizer, 207 

— system, 195 

Bituminous fuel combustion, 40, 

116, 112 
Blast furnace gas, 283 

— oil, 41, 47 

Blast pipe, variable, Macallan's, 

170, 240 
Blocks, fireclay, 41 
Boiler, Belleville, 110 

— choice of, 24, 25 

— water, capacity of, 132 

— Cherbourg, 264, 176 

— Du Temple type, 146 

— firefloat burner, 219 

— French torpedo boat, 38 

— Godard, 258 

— Guyot, 176 

— hydroleum special, 215 

— Lancashire, 145, 167, 168 

— Lancashire, Orde's system, 145 

— locomotive, 154 

— marine, 133 

— marine type, 173 

— Solignac, 25 

— underfired tubular, 205 

— water capacity of, 24 



Boiler, water tube, 169, 206 

— without grate, 169, 206, 213 

— Weir, 40, 121 

Boiling point of petroleum, 64 

Boring oil, 31 

Borneo oil, 212, 63, 208 

Brick, see Firebrick 

Brick arch, 67 

— linings, 67 
Bridge walls, 40 

British Thermal Unit, 294 

Buffle, 259 

Bulkheads, 128 

Bunker pipes of oil supply system, 

137 
Bunker pump, Weir's, 231 

— fuel oil, 231 
Burma oil, 281, 63 
Burner, Clarkson-Capel, 218 
Burners, see Atomizers, 250 

— Symon House, 257 
Burning of firebrick, 69 
Butane, 62 



Calculation of temperatures, 100 
Californian petroleum, 44, 45 
Calorific formula, 90 
Calorific power of Borneo oil, 63 

— Burma oil, 63 

— carbon, 78 

— Caucasus oil, 63 

— gases, 283 

— hydrogen, 81 

— liquid fuel, 53, 99, 281, 284 

— Clavenad on, 107 

— Texas oil, 53, 63 
Calorimetry, 91, 236 
Calorie, 90 

Calorimeter, Berthelot-Mahler, 237 

Canada oil, 281 

Capacity of boilers, water, 132 

Cap damper, chimney, 240 

Carbolic acid, 47 

Carbon, allotropic forms, 78, 115 

— amorphous, 78 

— as fuel, 78 

— atomic weight, 78 

— bisulphide, 79 

— calorific power of, 78 

— combustion of, 79 

— diamond, 78 

— dioxide, 79 
b— gaseous, 79 



INDEX 



301 



Carbon, graphitic, 78 

— heat of combustion, 78, 285 

— heat of conversion, 78, 79 

— in nature, 78 

— ''liquid," 45, 79 

— monoxide, 78 

— - properties of, 78, 285 

— solid, 78 

— vapour, 79 
Carbonic acid, 78 

— oxide, 78 
Carborundum, 67 

Cargo steamer, ordinary with oil 

fuel, 127 
Car hose, tank, 201 
Carriage of oil, 35, 228, 139 
Casing, 33 
Cast iron, 66 
Cement for oil pipes, 128 
Centigrade thermometer, 93 
Chamber, combustion, 73, 123 
Charcoal, see Amorphous carbon 
Chemical properties of air, 82 

— carbon, 78 

— hydrogen, 81 

— nitrogen, 84 

— oil, 62 

— oxygen, 83 

— petroleum, 62 

— Texas oil, 45 
Chemistry, Thermo-, 90 
Cherbourg, test at, 175 

— boiler, 176, 264 
Chicago Exhibition, 21 
Chimney area, 239 

— damper cap, 240 

— draught, 237 

— gases, 297 

Circular atomizers, 36, 262 
Classificationof fireclay goods, 76 
Clarkson-Capel burner, 218 

— preliminary heater, 219 
— ■ system, 218 

Clavenad on calorific capacity of 

fuel, 107 
Clay, see Fireclay 
C0 2 analysis, 233 
— - in furnace gases, 233 

— recorder, Ados, 236 

— recorder, Arndt, 236 

— Simmance Abady, 236 
Coal, analysis of, 112 

— anthracite, 116, 139 

— combustion of, 108 

— long-flaming, 117 



Coal, short-flaming, 117 

— Welsh, 117 

— and oil furnace, 134 

— and oil, comparative cost, 132, 

183, 286 

— production, 22 

— tar, 41 

Coefficient of expansion, oil, 129, 
281 

— water, 85 

— gases, 282 
Cofferdams, 128 

Coils, heating, 140, 155 
Combustion, air for, 37, 288, 290 

— oxygen for, 288, 290 

— of anthracite, 116, 139 

— of bituminous fuel, 40, 112, 116 

— calculations, 78, 100 

— smokeless, 108 

— of carbon, 79 

— of hydrogen, 81 

— chamber, refractory, 123 

— chamber, 73 

— imperfect, 108 

— heat of, 63, 109, 288 

— of liquid fuel, 63 

— of hydrocarbon, 109 

— of vaporized liquids, 218, 257 

— principles of, 39 

— temperature of, 100 

— volume of gases, 103 
Comparative costs, oil and coal, 

36, 59 
Compounds, hydrocarbon, 62, 112 
Compression, adiabatic, 242 

— of air, 242 

— compound, 242 

— diagrams, 242 

— isothermal, 242 
Conversion, metamorphic, of car- 
bon, 78, 11-5 

Construction of furnace, 203 
Controlling valves, 160 
Corsicana petroleum, 51 
Cost, comparison of coal and oil, 
35, 183 

— of oil, 36 
"Cracking," 52 
Cranes, oil, 230 
Creosote, 41, 46 
Cresylic acid, 47 

Crude oil, 41, 44, 281, 284 
Curves of compression of air, 244 
Curves of performance, Grazi- 
Tsaritzin Railway, 194 

U 



302 



INDEX 



d'Allest's atomizer, 261 
Damper, chimney cap, 240 
Danger of oil, 36 
Density of petroleum, 49, 65, 183 
Denton, Prof., on Texas oil, 59 

— evaporative duty, 59 

— cost of oil, 59 
Deterioration by storage, 65 
Diamond, 78 

Diesel engine, 270 
Dinas firebrick, 67 
Dissociation of steam, etc., 87, 97 

— gases, 97, 102 
Dioxide of carbon, 78 
Distillation, fractional, 48 
Distribution of liquid fuel, 228 
Dowlais firebrick, 67 
Draught, 237 

Draught gauge, 239 

Dudley's formula for relative cost 

of oil and coal, 183 
Dutch Navy, 130 
Dulong's formula, 91 

E 

Earnshaw on Texas oil, 51 
Econometer, Arndt, 236 
Economics of liquid fuel, 35 
Efficiency of evaporation, 58 

— Texas oil, 56 
Efflux of air, 238, 248 
Elementary atomizer, 256 
Ellis & Eave's air heater, 223 

— system, 222 
Endothermism, 90, 92 
English locomotive practice, 154 

— stationary practice, 208 
Ethane, 62, 82, 202, 282, 289 
Equivalent, Joule's, 285 

— mechanical, of heat, 285 
Evaporation, factors of, 295 

— per unit of various fuels, 104 
Evaporative duty, 59, 104, 291 

— efficiency, 58 
Everhart on Texas oil, 48 
Exothermism, 38, 92 
Expansion of oil, 129, 281 

— water, 85 
Explosions, 229 



Factors of evaporation, 295 
Factor, load, 24 



Fahrenheit thermometer, 93 
Feed, oil, 161 

Firebox, American locomotive, 
163, 171 

— Baldwin, 180 

— Cherbourg boiler, 176, 264 

— Holden, 165 

— Lancashire, 167 

— locomotive, 168 

— Southern Pacific, 171 

— Urquhart, 188 
Firebricks, 67 

— aluminous, 76 
Firebrick, analysis, 70, 71 

— arch, 67 

— burning, 69 

— classification, 76 

— carborundum, 67 

— carboniferous, 96 

— Dinas, 67 

— Dowlais, 67 

— French, 67, 70 

— general particulars, 67 

— Glenboig, 67 

— manufacture, 67 

— Newcastle, 67 

— Pearson, 68 

— silica, 70 

— Stourbridge, 67 
Fireclay, analysis, 70, 71 

— blocks, 41 

— Dinas, 67 

— Dowlais, 67 

— Gartcosh, 73 

— Glenboig, 67 

— Kilmarnock, 71 

— Newcastle, 67 

— Stourbridge, 67 
Flame, 117 

— testing, 118 

— length, 38, 117 
Flannery-Boyd system of oil fuel, 

129, 136 

— oil storage, 127 
Flash point, 39, 65, 130 
Flue gas analysis, 233 
Forbin, test of, 177 
Forced draught, 240 
Fractional distillation, 48 
French firebrick, 67 
French Navy tests, 175 

Fuel, evaporative, power of, 59, 
104, 291 

— gas, 283 

— oil, 212 



INDEX 



303 



Fuel, oil bunker, 142 

— oil distribution, 228 

— oil production, 26 

— pumping, 231 

— pump, Weir's, 231 

— oil tanks, 229 
Furieux, tests with, 175 
Furnace, Ellis & Eaves', 222 

— brickwork walls, etc., 146 

— construction, 203 

— Lancashire, 145, 165 

— firebricks, 67 

— lining, 39, 111, 146 

— locomotive, 168 

— management, 187 

— marine, 133, 173 

— oil and coal, 211 

— oil, 209 

— temperatures, 112, 81, 293 

— water tube, 213 
Fvardofski atomizer, 262 

— system, 262 



Gallon, American, 44, 183 

— English, 182 
Gallons, per barrel, 183 
Galician oil, 53 
Ganister, 67 
Gartcosh fireclay, 73 
Gas, analysis, 233 

— blast furnace, 283 

— density, 285, 290 

— dissociation of, 97 

— expansion of, 282 

— fuel, 283 

— hydrogen, 283 

— marsh, 283 

— sp. heat, 283, 284 

— tar, 43, 47, 214 

Gases, calorific capacity of, 283 

— of combustion, volume of, 103 

— chimney, 297 
Gaseous carbon, 79 
Gauge, draught, 239 
Gear, marine furnace, 133 
General arrangement, 137 

— Korting system, 152 
General considerations, 21 
Geology, 28 

German oil, 281 
Glass, violet, 121 
Glenboig clay, 67 
Godard boiler test, 258 



Graphite, 78 

Grate, boilers with, 211 

— boilers without, 210, 215, 206 
Gravity, 99 

— specific, 286, 287 
Grazi-Tsaritzin Railway, 184 

— curves of performance, 194 

— fuel tank, 231 

— locomotive, 189 

— oil distribution, 228 

— tender, 190 

Great Eastern Railway, 154 

— locomotives, 165 

— storage system, 229 

— tender, 165 
Griffin Engine, 270 
Guyot atomizer, 254 

— boiler, 176 



Hanover oil, 50, 53 
Hard water, 88 
Howden's system, 133, 143 
Heat, 92 

— of combustion of carbon, 80, 99 

— of combustion of petroleum, 

etc., 108, 109 

— latent, of carbon, 90 

— of dissociation, 79 

— latent, 96 

— mechanical equivalents of, 98 
■ — of metaphoric conversions, 78 

— quantity of, 92, 97 

— specific, 94 

— thermometric, 92 

— units, 90 

Heater, Clarkson-Capel prelimin- 
ary, 218 

— Ellis & Eaves air. 223 
Heating air, 166, 223 

— coils, 223 

— oil, 263 

Holden atomizer, 157 

— system, 154 
Hornsby Engine, 282 
Hose, 201 

Hose, tank car, 201 
Hoveler system, 267 
Howden's system, 133, 143 
Hydrocarbon compounds, 62,112 

— combustion of, 109 
Hydrogen, calorific power of, 81 

— combustion of, 81 

— gas, 81 



304 



INDEX 



Hydrogen properties of, 81 

— temperature of ignition, 82, 119 
Hydroleum special boiler, 215 

— atomizer, 250 

— system, 214 



Ignition temperature, 82, 119, 292 

Imperfect combustion, 102 

Indret, tests at, 176 

Injector, see Atomizer 

Interchange of coal and oil, 134 

Iron, cast, 66 

Isothermal compression, 242 



Japanese railways, 162 
Jeanne d'Arc, the, 174 
Joule, Dr., 98 

K 

Keller, tests by, 37 
Kelvin law, 26 
Kermode's atomizer, 250 

— system, 208 
Khodoung, s.s., 143 
Kilmarnock fireclay, 71 
Kilns, oil fired, 74 
Kimeridge clay, 28 
Korting atomizer, 153 

— system, 152 
Koudako oil, 49 



Laeisz, F. C, s.s., 143 
Lamp oil, 43, 218 
Lancashire boiler, 145, 167 
Latent heat, 96, 113 
Latitude and barometer, 83 
Length of flame, 38, 117 
Lighting up, 187 
Lima oil, 184 

Lining furnace, 39, 111, 146 
"Liquid" carbon, 45 

— combustion, 38 
Liquid fuel, 37 

— advantages of, 55 

— at sea, 127 

— containing oxygen, 47 

— distribution, 228 

— economics of, 35 



price of, 35, 59 



Liquid fuel, production, 26 
properties of, 49, 65, 183 

— system, Wallsend Slipway 

Co., 143, 146 

— varieties of, 43 
Load factor, 24 
Locomotive, American, 162, 178 

— boiler, 154, 178 

— Cherbourg, 264 

— firebox, 154, 163, 171 

— Fvardofski, 262 

— Great Eastern Railway, 154 

— practice, American, 162, 178 

— practice, English, 154 

— practice, Russian, 178 

— Southern Pacific, 171 

— Vladi Kavkaz Railway, 153 

— Urquhart, 184 

Low pressure air, 212, 269 
Loss by excess of air, 297 

M 

Mabery on Texas oil, 50 
Macallan variable blast pipe, 170 

240 
Management of furnace, 187, 204 
Manufacture of firebrick, 67 
Marine boiler, 173 

— type boiler, 173 

— furnace gear, 133, 173 
Marsh gas, see Methane 
Materials, 66 

Mazout or Mazut, see Astatki 
Mechanical stoking, 24 

— equivalent of heat, 98 
Metallurgy, application of liquid 

fuel to, 267 

Metal and refining furnace, 266 

Metamorphic conversion of car- 
bon, 78, 115 

Methane, 22, 82 

Meyer system, 172 

Milan, test on, 177 

Mixed system of coal and oil 
combustion, 35, 172 

Moat, round oil stores, 228 

Monoxide of carbon, 78 

Murex, s.s., 127, 133 



N 

Nacogdoches oil, 48 
Naphthalene, 47 
National Fuel Oil Co.'s 
9$ 



INDEX 



305 



Navy, British, 21, 130 

— Dutch, 130 

— French, 175 

— German, 130 

— Italian, 258 

— Russian, 65 
Newcastle fireclay, 67 

— coal, 47, 112 

New York, s.s., liquid fuel for, 138 
Nitrogen, 84 

— in atmosphere, 84 

— properties of, 84 
Nozzles of atomizers, 259 



Oil, Alsace, 53, 46 

— American, 44, 46 

— Baku, 53, 284, 36 

— Beaumont, 39 

— blast furnace, 47 

— boring, 31 

— Borneo, 63, 212, 208 

— Burma, 281, 63 

— California, 44, 54 

— Canada, 281, 46 

— Corsicana, 51 

— creosote, 46 

— crude, 183, 281, 284, 46 

— drilling, 32 

— fuel, 212, 284 

— Galicia, 53, 46 

— Gold Coast, 49 

— Hanover, 50, 53 

— Koudako, 49 

— lamp, 218, 43 

— Lima, 184 

— Nacogdoches, 48, 51 

— Pennsylvania, 46, 49, 53, 286 

— reduced, 44 

— residuum, 36, 42, 287 

— Roumanian, 46, 49 

— Russian, 46, 286 

— shale, 47 

— Sour Lake, 51 

— Texas, 45, 49 

— Wyoming, 86 

— Zante, 49 

— and coal, comparative cost, 38, 

286 

— and coal furnace, 136 

— burner, see Atomizers 

— calorific power, 281, 284 

— carriage of, 35, 139, 228 

— cranes, 231 



Oil engines, 271 

— expansion, 129, 281 

— explosions, 229 

— distribution, 228 

— feed, 161 
Oil furnaces, 

— furnace, Baldwin, 178 

— engines, 271 

— Cornish, see Lancashire 

— Holden, 165, 168 

— Lancashire, 168 

— locomotive, 154-178 

— water tube boiler, 169 
Oil heating, 263 

— pressure, 269 

— pipes, 229 

— pump, 231 

— pumping system, 196, 32 

— ratio to coal, 54 

— regulation, 161, 179 

— regulator, 161, 179 

— safety moat, 228 

— service pumps, 196, 231 

— steamers, recent, 129 

— storage, 127, 228 

— stratification, 30 

— tank steamer, 138 
Orde atomizer, 144 

— boiler, Lancashire, 145 

— on liquid fuel, 63 

— system, 140, 143 

— water-tube boiler, 141 
Orsat-Lunge apparatus, 236 
Oxygen, 83 



Packman, s.s.. 133 

Pakin, test on, 177 

Paraffin, 221 

Paul, Dr., on liquid fuel, 62 

Pearson firebricks, 68 

Pelouze and Cahours on hydrocar- 
bons, 64 

Pennsylvania oil, 49, 286 

Performance curves, Grazi-Tsarit- 
zin Railway, 194 

Petroleum 

— American, 44 

— analysis of, 48 

— Baku, 53, 284 

— Borneo, 212, 63 

— Burma, 281, 63 

— boiling point, 64 

— California, 44, 54 

— combustion of, 109, 218, 257 



S06 



INDEX 



Petroleum, Corsicana, 51 

— drilling, 32 

— fuel, 183 

— geology, 28 

— production of, 26 

— properties of, 49, 65, 183 

— pumping, 32 

— residuum, 36, 42, 287, 291 

— Russian, 46, 286 

— storage precautions, 228 

— Texas, 45, 49 
Phillips on Texas oil, 49 
Physical properties of oil, 49, 65, 

183 
Pipes, 88, 229 

— bunker, 128, 137 

— jointing, 128 

— jointing cement, 128 

— water, 88 

Pood, its equivalent, 230 
Power to compress air, 247 
Precautions in oil storage, 228 
Preliminary heating, 218 
Pressure systems, 196 
Price of oil, 35, 59 

— per barrel, 36, 54, 59 

— per gallon, 36, 44 
Principles of liquid fuel combus- 
tion, 38 

Production of coal, 22 
Propane, 62, 82 
Properties of air, 82 

— American oil, 44, 46 

— Borneo oil, 63, 208, 212 

— carbon, 78, 285 

— firebricks, 67 

— fireclay 67 

— gases, 283 

— hydrogen, 81 

— liquid fuel, 49, 65, 183 

— nitrogen, 84 

— oxygen, 83 

— petroleum, 49 

— Russian oil, 46, 256 

— Texas oil, 45, 51 

— water, 84 

Proportions of atomizers, 261 
Propylene, 82 
Pulverizers, see Atomizers 
Pump, Weir's bunker, 232 

— Weir's oil, 232 
Pumping systems, 196 
Pumps, oil, 231 
Pyrometers, 94 



Q 

Quantity of heat, 92, 97 

R 

Ragosine effect of steam on oil, 260 
Ratio, oil to coal, 38 
Reaumur's thermometer, 93 
Reduced oils, 44 
Refractory combustion chamber, 
73 

— linings, 39, 73, 111, 146 
Regulating gear, 161, 179 
Regulation of oil, 161, 179 
Regulator, air, 202 

— oil, Baldwin 179 

— oil, G.E. Rly., 161 
Relative cost, oil and coal, 132, 

183, 268, 286, 191 
Residuum, 36, 42, 197 
Ringelmann's smoke chart, 123 
Riveting, 128 
Roumanian oil, 49 
Rules for liquid fuel ships, 127 
Rusden-Eeles atomizer, 134 
Russian locomotives, 191 

— Navy, 65 

— oil, 46 

Ruston Proctor Engine, 271 

S 
Safety moat round tanks, 228 
St. Clair Deville, 102 
Salts, solubility of, 87 
Sea water, 88 

Serpollet on vaporizing, 263 
Service, oil pumps, 231, 196 
>Shale oil, 47 

— tar, 47 
Silica, 67-77 
Siloxicon 77 

Simmance Abady C0 2 recorder, 

236 
Sithonia, s.s., 143 
Small tube boiler, 141 ' 
Smoke, 82, 109 

— chart, Ringelmann's, 123 

— prevention, 109 
Soft water, 88 
Soliani atomizer, 263 
Solignac boiler, 25 
Solubility in water of salts, 87 
Soot, 82 

Sour Lake oil, 51 
Southern Pacific Railway, 36, 54, 
171, 264 



INDEX 



307 



Specific gravity, 46, 49, 65, 164 
Specific heat, 94 

— gases, 95 

— ice, 86 

— solids, 284 

— water, 86 
Sprayer, see Atomizer 
Springfield system, 269 
Stationary practice, American, 

195 

— English, 208 
Steam, as fuel, 15 

— atomizing, 133 

— dissociation by heat, 87, 97 

— per pound of oil, 258 

— ships, F. G. Lacisz, 143 

— Murex, 127, 133 

— Newyork, 139 

— Sithonia, 143 

— Syrian 143 

— Tanglier, 133 

— Trocas, 129, 134 
Steam, superheated, 294, 143 
Steamer, cargo with oil fuel, 127 

— recent oil, 138 

— tank with oil fuel, 129 
Steel, 66 

Steel tubes, 66 
Storage of oil, 228 

— safety moat, 228 

— system, G.E. Rly., 229 

— tank, oil, 228 
Stourbridge clay, 67 

— firebricks, 67 
Subweolden, boring, 29 
Sulphur in oil, 36, 59 
Sumatra oil, 49 
Superheated steam, 294 
Supply of water, 84 

— tank, oil, 231 

— system, bunker pipes, 137, 141 
Surcouf, test of, 177 
Swenssor atomizer, 256 
Syrian, s.s., 143 

System, Aerated Fuel Co., 267 

— Baldwin Co., 178 

— Billow, 195 

— Clarkson-Capel, 218 

— distribution, 228 

— Ellis & Eaves, 222 

— Flannery Boyd, 136 

— Fvardofski, 262 

— Guyot, 254 

— Holden's, 154 

— Hoveler, 267 



System Howden's, 133 143 

— hydroleum, 214 

— Kermode's, 208 

— Korting, 143, 152 

— Meyer, 172 

— mixed, 37, 172 

— National Fuel Co., 195 

— Orde's, 140, 143 

— Pumping, 231, 198 

— Rusden-Eeles, 134, 143 

— Springfield, 269 

— Symon House, 257 

— Urquhart, 184 

— Wallsend Slipway Co.'s, 143, 

146 



Tanglier, s.s., 133 
Tank, car hose, 201 

— oil supply, 231 

— steamer, 138 

— storage, 228 

— underground, 230 
Tar, 41, 43, 47, 214, 237 

— properties of, 237 

— water gas, test of, 215 

— shale, 47 
Temperature, 92, 284, 293 

— calculation of, 100 

— flame, 112, 259 

— furnace, 112 

— of combination, 101 

— of ignition, 82, 292 
Tender, fuel, 186 

— G.E. Rly., 165 

— Grazi-Tsaritsin Railway, 186, 

190 
Test of air atomizing, 226 

— Beaumont oil, 57 

— Borneo oil, 208, 211 

— Furieux, 175 

— marine boiler, 222-227 

— Texas oil, 56, 48 

Tests at Cherbourg, 175, 264 

— at Birkenhead, 212 

— at Indret, 176 

— Godard boiler, 258 
■ — Russian oil, 37 
Texas oil, 45, 51 

— analysis, 48, 51 

— calorific power of, 53 

— carriage of, 35 

— chemistry of, 48 

— costs, 59 



308 



INDEX 



Texas, density of, 49 

— efficiency of, 56 

— specific gravity of, 49 

— tests of, 56 
Thermal units, 90, 294 
Thermo-chemistry, 90 
Thermometer, 93 

Thiele on Texas oil, 45, 51 
Torpedo boat, 38 

— boiler, French, 260 
Trinidad, 28 
Trocas, s.s., 129, 134 
Tubular boiler, underfired, 205 
Tunnels, Railway, 171 
Tuyere, air, 202 

U 

U gauge, 239 

Underfired tubular boiler, 205 

Units of heat, 90, 97 

— thermal, 97 

— weight, 85, 98 

— work, 98 
Urquhart atomizer, 193 

— locomotive, 191 

— system, 184 

— tender, 188 

Useful figures, 87, 89, 292 



Vaporization, heat of, 106, 117 
Vaporized liquids, combustion of, 

218 
Vaporizer, 273, 275 
Vaporizing, 43, 216, 218, 276 

— carbon, 78, 79 

Variable blast pipe, Macallan's, 

170, 240 
Varieties of liquid fuel, 43 
Velocity of efflux of air, 238, 248 

— draught, 237 

— water in pipes, 88 
Ventilation, 128 
Verein-Deutsche ingenieur, 91 
Violet rays in flame, 120 
Volatile constituents of petro- 
leum, 36, 39, 42, 47 

Volume and weight of atmo- 
sphere gases, 293 

— gases, 289 

— petroleum, 183 

— of combustion gases, 289 



W 

Wallsend Slipway Co., 143, 146 

— Atomizer, 148 

— furnace brickwork, 146 

— latest system, 149 
Warming oil fuel, 263 

War vessels, Sir F. Flannery on. 

130 
Water capacity of boilers, 24 

— compressibility, 85 

— data, 85 

— expansion by heat, 85 

— flow of, 88 

— gas tar, 215 

— gauge, 239 

— hardness, 88 

— in oil, 68 

— latent heat of, 84 

— pipes, 88 

— properties of, 84, 294 

— pure, 84, 294 

— solubility of salts in, 88 

— source of, 84 

— specific heat, 86 

— supply, 84 

— useful data, 89 

— weight, 87 

Water-tube boiler, Guyot, 176 

— Hydroleum, 215 

— Orde's system for liquid fuel, 

140 

— Wealden, 29 

— Weir's, 40, 121 

— without grate, 169, 206 
Weight of air, 82, 289 

— gases, 289 

— hydrogen, 81, 289 

— firebrick, 

— oil, 58 

— oil per barrel, 58 

— oil per gallon, 58 

— oxygen, 84, 289 

— nitrogen 84, 289 

— water, 85, 294 
Weir's boiler, 121, 40 

— oil pump, 231 
Welsh coal, 117 
Williams atomizer, 56 
Work units, 98 
Wyoming oil, 46 

Z 

Zante oil, 49 



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